diff --git a/NEWS b/NEWS
index 145d8cb69..4f3694e1f 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,13 @@ Features:
   * Additional functions bson_iter_overwrite_date_time, bson_iter_overwrite_oid,
     and bson_iter_overwrite_timestamp. All fixed-length BSON values can now be
     updated in place.
+  * The event types passed to command-monitoring and SDAM-monitoring callbacks,
+    such as mongoc_apm_command_started_t* or mongoc_apm_server_changed_t*, are
+    no longer declared "const". These event structs are still practically const
+    because the only functions declared for them are for retrieving fields, not
+    setting them. However, declaring these event parameters non-const allows
+    you to call functions like mongoc_topology_description_has_writable_server
+    that require a non-const parameter.
 
 Bug fixes:
 
diff --git a/src/libmongoc/doc/mongoc_apm_set_command_failed_cb.rst b/src/libmongoc/doc/mongoc_apm_set_command_failed_cb.rst
index 5f9d07598..719ddd37d 100644
--- a/src/libmongoc/doc/mongoc_apm_set_command_failed_cb.rst
+++ b/src/libmongoc/doc/mongoc_apm_set_command_failed_cb.rst
@@ -9,7 +9,7 @@ Synopsis
 .. code-block:: c
 
   typedef void (*mongoc_apm_command_failed_cb_t) (
-     const mongoc_apm_command_failed_t *event);
+     mongoc_apm_command_failed_t *event);
 
   void
   mongoc_apm_set_command_failed_cb (mongoc_apm_callbacks_t *callbacks,
diff --git a/src/libmongoc/doc/mongoc_apm_set_command_started_cb.rst b/src/libmongoc/doc/mongoc_apm_set_command_started_cb.rst
index a64b2b2f1..d83ad0f1a 100644
--- a/src/libmongoc/doc/mongoc_apm_set_command_started_cb.rst
+++ b/src/libmongoc/doc/mongoc_apm_set_command_started_cb.rst
@@ -9,7 +9,7 @@ Synopsis
 .. code-block:: c
 
   typedef void (*mongoc_apm_command_started_cb_t) (
-     const mongoc_apm_command_started_t *event);
+     mongoc_apm_command_started_t *event);
 
   void
   mongoc_apm_set_command_started_cb (mongoc_apm_callbacks_t *callbacks,
diff --git a/src/libmongoc/doc/mongoc_apm_set_command_succeeded_cb.rst b/src/libmongoc/doc/mongoc_apm_set_command_succeeded_cb.rst
index 2d2e9fefe..79a62bf21 100644
--- a/src/libmongoc/doc/mongoc_apm_set_command_succeeded_cb.rst
+++ b/src/libmongoc/doc/mongoc_apm_set_command_succeeded_cb.rst
@@ -9,7 +9,7 @@ Synopsis
 .. code-block:: c
 
   typedef void (*mongoc_apm_command_succeeded_cb_t) (
-     const mongoc_apm_command_succeeded_t *event);
+     mongoc_apm_command_succeeded_t *event);
 
   void
   mongoc_apm_set_command_succeeded_cb (mongoc_apm_callbacks_t *callbacks,
diff --git a/src/libmongoc/doc/mongoc_apm_set_server_changed_cb.rst b/src/libmongoc/doc/mongoc_apm_set_server_changed_cb.rst
index 1aa742566..0434b2b44 100644
--- a/src/libmongoc/doc/mongoc_apm_set_server_changed_cb.rst
+++ b/src/libmongoc/doc/mongoc_apm_set_server_changed_cb.rst
@@ -9,7 +9,7 @@ Synopsis
 .. code-block:: c
 
   typedef void (*mongoc_apm_server_changed_cb_t) (
-     const mongoc_apm_server_changed_t *event);
+     mongoc_apm_server_changed_t *event);
 
   void
   mongoc_apm_set_server_changed_cb (mongoc_apm_callbacks_t *callbacks,
diff --git a/src/libmongoc/doc/mongoc_apm_set_server_closed_cb.rst b/src/libmongoc/doc/mongoc_apm_set_server_closed_cb.rst
index 738968f3e..a96475ace 100644
--- a/src/libmongoc/doc/mongoc_apm_set_server_closed_cb.rst
+++ b/src/libmongoc/doc/mongoc_apm_set_server_closed_cb.rst
@@ -9,7 +9,7 @@ Synopsis
 .. code-block:: c
 
   typedef void (*mongoc_apm_server_closed_cb_t) (
-     const mongoc_apm_server_closed_t *event);
+     mongoc_apm_server_closed_t *event);
 
   void
   mongoc_apm_set_server_closed_cb (mongoc_apm_callbacks_t *callbacks,
diff --git a/src/libmongoc/doc/mongoc_apm_set_server_heartbeat_failed_cb.rst b/src/libmongoc/doc/mongoc_apm_set_server_heartbeat_failed_cb.rst
index 44ea1b054..84ad49c04 100644
--- a/src/libmongoc/doc/mongoc_apm_set_server_heartbeat_failed_cb.rst
+++ b/src/libmongoc/doc/mongoc_apm_set_server_heartbeat_failed_cb.rst
@@ -9,7 +9,7 @@ Synopsis
 .. code-block:: c
 
   typedef void (*mongoc_apm_server_heartbeat_failed_cb_t) (
-     const mongoc_apm_server_heartbeat_failed_t *event);
+     mongoc_apm_server_heartbeat_failed_t *event);
 
   void
   mongoc_apm_set_server_heartbeat_failed_cb (mongoc_apm_callbacks_t *callbacks,
diff --git a/src/libmongoc/doc/mongoc_apm_set_server_heartbeat_started_cb.rst b/src/libmongoc/doc/mongoc_apm_set_server_heartbeat_started_cb.rst
index 682236655..2e46b2293 100644
--- a/src/libmongoc/doc/mongoc_apm_set_server_heartbeat_started_cb.rst
+++ b/src/libmongoc/doc/mongoc_apm_set_server_heartbeat_started_cb.rst
@@ -9,7 +9,7 @@ Synopsis
 .. code-block:: c
 
   typedef void (*mongoc_apm_server_heartbeat_started_cb_t) (
-     const mongoc_apm_server_heartbeat_started_t *event);
+     mongoc_apm_server_heartbeat_started_t *event);
 
   void
   mongoc_apm_set_server_heartbeat_started_cb (mongoc_apm_callbacks_t *callbacks,
diff --git a/src/libmongoc/doc/mongoc_apm_set_server_heartbeat_succeeded_cb.rst b/src/libmongoc/doc/mongoc_apm_set_server_heartbeat_succeeded_cb.rst
index 31d0739da..4bf1c3599 100644
--- a/src/libmongoc/doc/mongoc_apm_set_server_heartbeat_succeeded_cb.rst
+++ b/src/libmongoc/doc/mongoc_apm_set_server_heartbeat_succeeded_cb.rst
@@ -9,7 +9,7 @@ Synopsis
 .. code-block:: c
 
   typedef void (*mongoc_apm_server_heartbeat_succeeded_cb_t) (
-     const mongoc_apm_server_heartbeat_succeeded_t *event);
+     mongoc_apm_server_heartbeat_succeeded_t *event);
 
   void
   mongoc_apm_set_server_heartbeat_succeeded_cb (mongoc_apm_callbacks_t *callbacks,
diff --git a/src/libmongoc/doc/mongoc_apm_set_server_opening_cb.rst b/src/libmongoc/doc/mongoc_apm_set_server_opening_cb.rst
index d51b6418f..a744711a5 100644
--- a/src/libmongoc/doc/mongoc_apm_set_server_opening_cb.rst
+++ b/src/libmongoc/doc/mongoc_apm_set_server_opening_cb.rst
@@ -9,7 +9,7 @@ Synopsis
 .. code-block:: c
 
   typedef void (*mongoc_apm_server_opening_cb_t) (
-     const mongoc_apm_server_opening_t *event);
+     mongoc_apm_server_opening_t *event);
 
   void
   mongoc_apm_set_server_opening_cb (mongoc_apm_callbacks_t *callbacks,
diff --git a/src/libmongoc/doc/mongoc_apm_set_topology_changed_cb.rst b/src/libmongoc/doc/mongoc_apm_set_topology_changed_cb.rst
index e5dab6fb2..acaffcd4d 100644
--- a/src/libmongoc/doc/mongoc_apm_set_topology_changed_cb.rst
+++ b/src/libmongoc/doc/mongoc_apm_set_topology_changed_cb.rst
@@ -9,7 +9,7 @@ Synopsis
 .. code-block:: c
 
   typedef void (*mongoc_apm_topology_changed_cb_t) (
-     const mongoc_apm_topology_changed_t *event);
+     mongoc_apm_topology_changed_t *event);
 
   void
   mongoc_apm_set_topology_changed_cb (mongoc_apm_callbacks_t *callbacks,
diff --git a/src/libmongoc/doc/mongoc_apm_set_topology_closed_cb.rst b/src/libmongoc/doc/mongoc_apm_set_topology_closed_cb.rst
index 2f3d6dec2..5df4b97c5 100644
--- a/src/libmongoc/doc/mongoc_apm_set_topology_closed_cb.rst
+++ b/src/libmongoc/doc/mongoc_apm_set_topology_closed_cb.rst
@@ -9,7 +9,7 @@ Synopsis
 .. code-block:: c
 
   typedef void (*mongoc_apm_topology_closed_cb_t) (
-     const mongoc_apm_topology_closed_t *event);
+     mongoc_apm_topology_closed_t *event);
 
   void
   mongoc_apm_set_topology_closed_cb (mongoc_apm_callbacks_t *callbacks,
diff --git a/src/libmongoc/doc/mongoc_apm_set_topology_opening_cb.rst b/src/libmongoc/doc/mongoc_apm_set_topology_opening_cb.rst
index b20f4114f..bed5be751 100644
--- a/src/libmongoc/doc/mongoc_apm_set_topology_opening_cb.rst
+++ b/src/libmongoc/doc/mongoc_apm_set_topology_opening_cb.rst
@@ -9,7 +9,7 @@ Synopsis
 .. code-block:: c
 
   typedef void (*mongoc_apm_topology_opening_cb_t) (
-     const mongoc_apm_topology_opening_t *event);
+     mongoc_apm_topology_opening_t *event);
 
   void
   mongoc_apm_set_topology_opening_cb (mongoc_apm_callbacks_t *callbacks,
diff --git a/src/libmongoc/doc/mongoc_apm_topology_changed_get_context.rst b/src/libmongoc/doc/mongoc_apm_topology_changed_get_context.rst
index 1db225949..78c94331f 100644
--- a/src/libmongoc/doc/mongoc_apm_topology_changed_get_context.rst
+++ b/src/libmongoc/doc/mongoc_apm_topology_changed_get_context.rst
@@ -10,7 +10,7 @@ Synopsis
 
   void *
   mongoc_apm_topology_changed_get_context (
-     const mongoc_apm_topology_changed_t *event);
+     mongoc_apm_topology_changed_t *event);
 
 Returns this event's context.
 
diff --git a/src/libmongoc/doc/mongoc_apm_topology_changed_get_new_description.rst b/src/libmongoc/doc/mongoc_apm_topology_changed_get_new_description.rst
index a30e80a2b..2a4defc4a 100644
--- a/src/libmongoc/doc/mongoc_apm_topology_changed_get_new_description.rst
+++ b/src/libmongoc/doc/mongoc_apm_topology_changed_get_new_description.rst
@@ -8,9 +8,9 @@ Synopsis
 
 .. code-block:: c
 
-  const mongoc_topology_description_t *
+  mongoc_topology_description_t *
   mongoc_apm_topology_changed_get_new_description (
-     const mongoc_apm_topology_changed_t *event);
+     mongoc_apm_topology_changed_t *event);
 
 Returns this event's new description. The data is only valid in the scope of the callback that receives this event; copy it if it will be accessed after the callback returns.
 
diff --git a/src/libmongoc/doc/mongoc_apm_topology_changed_get_previous_description.rst b/src/libmongoc/doc/mongoc_apm_topology_changed_get_previous_description.rst
index 82accced9..2aef6ca3c 100644
--- a/src/libmongoc/doc/mongoc_apm_topology_changed_get_previous_description.rst
+++ b/src/libmongoc/doc/mongoc_apm_topology_changed_get_previous_description.rst
@@ -8,9 +8,9 @@ Synopsis
 
 .. code-block:: c
 
-  const mongoc_topology_description_t *
+  mongoc_topology_description_t *
   mongoc_apm_topology_changed_get_previous_description (
-     const mongoc_apm_topology_changed_t *event);
+     mongoc_apm_topology_changed_t *event);
 
 Returns this event's previous description. The data is only valid in the scope of the callback that receives this event; copy it if it will be accessed after the callback returns.
 
diff --git a/src/libmongoc/examples/example-command-monitoring.c b/src/libmongoc/examples/example-command-monitoring.c
index fe154dce8..cb778c7a6 100644
--- a/src/libmongoc/examples/example-command-monitoring.c
+++ b/src/libmongoc/examples/example-command-monitoring.c
@@ -15,7 +15,7 @@ typedef struct {
 
 
 void
-command_started (const mongoc_apm_command_started_t *event)
+command_started (mongoc_apm_command_started_t *event)
 {
    char *s;
 
@@ -33,7 +33,7 @@ command_started (const mongoc_apm_command_started_t *event)
 
 
 void
-command_succeeded (const mongoc_apm_command_succeeded_t *event)
+command_succeeded (mongoc_apm_command_succeeded_t *event)
 {
    char *s;
 
@@ -50,7 +50,7 @@ command_succeeded (const mongoc_apm_command_succeeded_t *event)
 
 
 void
-command_failed (const mongoc_apm_command_failed_t *event)
+command_failed (mongoc_apm_command_failed_t *event)
 {
    bson_error_t error;
 
diff --git a/src/libmongoc/examples/example-sdam-monitoring.c b/src/libmongoc/examples/example-sdam-monitoring.c
index 6e90fddbe..6734d7e58 100644
--- a/src/libmongoc/examples/example-sdam-monitoring.c
+++ b/src/libmongoc/examples/example-sdam-monitoring.c
@@ -21,7 +21,7 @@ typedef struct {
 
 
 static void
-server_changed (const mongoc_apm_server_changed_t *event)
+server_changed (mongoc_apm_server_changed_t *event)
 {
    stats_t *context;
    const mongoc_server_description_t *prev_sd, *new_sd;
@@ -40,7 +40,7 @@ server_changed (const mongoc_apm_server_changed_t *event)
 
 
 static void
-server_opening (const mongoc_apm_server_opening_t *event)
+server_opening (mongoc_apm_server_opening_t *event)
 {
    stats_t *context;
 
@@ -53,7 +53,7 @@ server_opening (const mongoc_apm_server_opening_t *event)
 
 
 static void
-server_closed (const mongoc_apm_server_closed_t *event)
+server_closed (mongoc_apm_server_closed_t *event)
 {
    stats_t *context;
 
@@ -66,11 +66,11 @@ server_closed (const mongoc_apm_server_closed_t *event)
 
 
 static void
-topology_changed (const mongoc_apm_topology_changed_t *event)
+topology_changed (mongoc_apm_topology_changed_t *event)
 {
    stats_t *context;
-   const mongoc_topology_description_t *prev_td;
-   const mongoc_topology_description_t *new_td;
+   mongoc_topology_description_t *prev_td;
+   mongoc_topology_description_t *new_td;
    mongoc_server_description_t **prev_sds;
    size_t n_prev_sds;
    mongoc_server_description_t **new_sds;
@@ -113,7 +113,7 @@ topology_changed (const mongoc_apm_topology_changed_t *event)
 
 
 static void
-topology_opening (const mongoc_apm_topology_opening_t *event)
+topology_opening (mongoc_apm_topology_opening_t *event)
 {
    stats_t *context;
 
@@ -125,7 +125,7 @@ topology_opening (const mongoc_apm_topology_opening_t *event)
 
 
 static void
-topology_closed (const mongoc_apm_topology_closed_t *event)
+topology_closed (mongoc_apm_topology_closed_t *event)
 {
    stats_t *context;
 
@@ -137,7 +137,7 @@ topology_closed (const mongoc_apm_topology_closed_t *event)
 
 
 static void
-server_heartbeat_started (const mongoc_apm_server_heartbeat_started_t *event)
+server_heartbeat_started (mongoc_apm_server_heartbeat_started_t *event)
 {
    stats_t *context;
 
@@ -151,8 +151,7 @@ server_heartbeat_started (const mongoc_apm_server_heartbeat_started_t *event)
 
 
 static void
-server_heartbeat_succeeded (
-   const mongoc_apm_server_heartbeat_succeeded_t *event)
+server_heartbeat_succeeded (mongoc_apm_server_heartbeat_succeeded_t *event)
 {
    stats_t *context;
    char *reply;
@@ -174,7 +173,7 @@ server_heartbeat_succeeded (
 
 
 static void
-server_heartbeat_failed (const mongoc_apm_server_heartbeat_failed_t *event)
+server_heartbeat_failed (mongoc_apm_server_heartbeat_failed_t *event)
 {
    stats_t *context;
    bson_error_t error;
diff --git a/src/libmongoc/src/mongoc/mongoc-apm-private.h b/src/libmongoc/src/mongoc/mongoc-apm-private.h
index 4c472248d..f6710791b 100644
--- a/src/libmongoc/src/mongoc/mongoc-apm-private.h
+++ b/src/libmongoc/src/mongoc/mongoc-apm-private.h
@@ -109,8 +109,8 @@ struct _mongoc_apm_server_closed_t {
 
 struct _mongoc_apm_topology_changed_t {
    bson_oid_t topology_id;
-   const mongoc_topology_description_t *previous_description;
-   const mongoc_topology_description_t *new_description;
+   mongoc_topology_description_t *previous_description;
+   mongoc_topology_description_t *new_description;
    void *context;
 };
 
diff --git a/src/libmongoc/src/mongoc/mongoc-apm.c b/src/libmongoc/src/mongoc/mongoc-apm.c
index 50a2a5e15..e819a1615 100644
--- a/src/libmongoc/src/mongoc/mongoc-apm.c
+++ b/src/libmongoc/src/mongoc/mongoc-apm.c
@@ -521,17 +521,17 @@ mongoc_apm_topology_changed_get_topology_id (
 }
 
 
-const mongoc_topology_description_t *
+mongoc_topology_description_t *
 mongoc_apm_topology_changed_get_previous_description (
-   const mongoc_apm_topology_changed_t *event)
+   mongoc_apm_topology_changed_t *event)
 {
    return event->previous_description;
 }
 
 
-const mongoc_topology_description_t *
+mongoc_topology_description_t *
 mongoc_apm_topology_changed_get_new_description (
-   const mongoc_apm_topology_changed_t *event)
+   mongoc_apm_topology_changed_t *event)
 {
    return event->new_description;
 }
diff --git a/src/libmongoc/src/mongoc/mongoc-apm.h b/src/libmongoc/src/mongoc/mongoc-apm.h
index 9dd5667a6..6f1c8c730 100644
--- a/src/libmongoc/src/mongoc/mongoc-apm.h
+++ b/src/libmongoc/src/mongoc/mongoc-apm.h
@@ -145,8 +145,7 @@ MONGOC_EXPORT (void)
 mongoc_apm_command_failed_get_error (const mongoc_apm_command_failed_t *event,
                                      bson_error_t *error);
 MONGOC_EXPORT (const bson_t *)
-mongoc_apm_command_failed_get_reply (
-   const mongoc_apm_command_failed_t *event);
+mongoc_apm_command_failed_get_reply (const mongoc_apm_command_failed_t *event);
 MONGOC_EXPORT (int64_t)
 mongoc_apm_command_failed_get_request_id (
    const mongoc_apm_command_failed_t *event);
@@ -205,12 +204,12 @@ mongoc_apm_server_closed_get_context (const mongoc_apm_server_closed_t *event);
 MONGOC_EXPORT (void)
 mongoc_apm_topology_changed_get_topology_id (
    const mongoc_apm_topology_changed_t *event, bson_oid_t *topology_id);
-MONGOC_EXPORT (const mongoc_topology_description_t *)
+MONGOC_EXPORT (mongoc_topology_description_t *)
 mongoc_apm_topology_changed_get_previous_description (
-   const mongoc_apm_topology_changed_t *event);
-MONGOC_EXPORT (const mongoc_topology_description_t *)
+   mongoc_apm_topology_changed_t *event);
+MONGOC_EXPORT (mongoc_topology_description_t *)
 mongoc_apm_topology_changed_get_new_description (
-   const mongoc_apm_topology_changed_t *event);
+   mongoc_apm_topology_changed_t *event);
 MONGOC_EXPORT (void *)
 mongoc_apm_topology_changed_get_context (
    const mongoc_apm_topology_changed_t *event);
@@ -278,29 +277,29 @@ mongoc_apm_server_heartbeat_failed_get_context (
  */
 
 typedef void (*mongoc_apm_command_started_cb_t) (
-   const mongoc_apm_command_started_t *event);
+   mongoc_apm_command_started_t *event);
 typedef void (*mongoc_apm_command_succeeded_cb_t) (
-   const mongoc_apm_command_succeeded_t *event);
+   mongoc_apm_command_succeeded_t *event);
 typedef void (*mongoc_apm_command_failed_cb_t) (
-   const mongoc_apm_command_failed_t *event);
+   mongoc_apm_command_failed_t *event);
 typedef void (*mongoc_apm_server_changed_cb_t) (
-   const mongoc_apm_server_changed_t *event);
+   mongoc_apm_server_changed_t *event);
 typedef void (*mongoc_apm_server_opening_cb_t) (
-   const mongoc_apm_server_opening_t *event);
+   mongoc_apm_server_opening_t *event);
 typedef void (*mongoc_apm_server_closed_cb_t) (
-   const mongoc_apm_server_closed_t *event);
+   mongoc_apm_server_closed_t *event);
 typedef void (*mongoc_apm_topology_changed_cb_t) (
-   const mongoc_apm_topology_changed_t *event);
+   mongoc_apm_topology_changed_t *event);
 typedef void (*mongoc_apm_topology_opening_cb_t) (
-   const mongoc_apm_topology_opening_t *event);
+   mongoc_apm_topology_opening_t *event);
 typedef void (*mongoc_apm_topology_closed_cb_t) (
-   const mongoc_apm_topology_closed_t *event);
+   mongoc_apm_topology_closed_t *event);
 typedef void (*mongoc_apm_server_heartbeat_started_cb_t) (
-   const mongoc_apm_server_heartbeat_started_t *event);
+   mongoc_apm_server_heartbeat_started_t *event);
 typedef void (*mongoc_apm_server_heartbeat_succeeded_cb_t) (
-   const mongoc_apm_server_heartbeat_succeeded_t *event);
+   mongoc_apm_server_heartbeat_succeeded_t *event);
 typedef void (*mongoc_apm_server_heartbeat_failed_cb_t) (
-   const mongoc_apm_server_heartbeat_failed_t *event);
+   mongoc_apm_server_heartbeat_failed_t *event);
 
 /*
  * registering callbacks
diff --git a/src/libmongoc/src/mongoc/mongoc-topology-description-apm-private.h b/src/libmongoc/src/mongoc/mongoc-topology-description-apm-private.h
index 356e2a0e8..88add811a 100644
--- a/src/libmongoc/src/mongoc/mongoc-topology-description-apm-private.h
+++ b/src/libmongoc/src/mongoc/mongoc-topology-description-apm-private.h
@@ -50,8 +50,8 @@ _mongoc_topology_description_monitor_opening (
 
 void
 _mongoc_topology_description_monitor_changed (
-   const mongoc_topology_description_t *prev_td,
-   const mongoc_topology_description_t *new_td);
+   mongoc_topology_description_t *prev_td,
+   mongoc_topology_description_t *new_td);
 
 void
 _mongoc_topology_description_monitor_closed (
diff --git a/src/libmongoc/src/mongoc/mongoc-topology-description-apm.c b/src/libmongoc/src/mongoc/mongoc-topology-description-apm.c
index 0ae897a20..6493f4ece 100644
--- a/src/libmongoc/src/mongoc/mongoc-topology-description-apm.c
+++ b/src/libmongoc/src/mongoc/mongoc-topology-description-apm.c
@@ -128,8 +128,8 @@ _mongoc_topology_description_monitor_opening (mongoc_topology_description_t *td)
 /* TopologyDescriptionChangedEvent */
 void
 _mongoc_topology_description_monitor_changed (
-   const mongoc_topology_description_t *prev_td,
-   const mongoc_topology_description_t *new_td)
+   mongoc_topology_description_t *prev_td,
+   mongoc_topology_description_t *new_td)
 {
    if (new_td->apm_callbacks.topology_changed) {
       mongoc_apm_topology_changed_t event;
diff --git a/src/libmongoc/tests/json-test-monitoring.c b/src/libmongoc/tests/json-test-monitoring.c
index 877865f9e..09d9ac045 100644
--- a/src/libmongoc/tests/json-test-monitoring.c
+++ b/src/libmongoc/tests/json-test-monitoring.c
@@ -258,7 +258,7 @@ assert_host_in_uri (const mongoc_host_list_t *host, const mongoc_uri_t *uri)
 
 
 static void
-started_cb (const mongoc_apm_command_started_t *event)
+started_cb (mongoc_apm_command_started_t *event)
 {
    json_test_ctx_t *ctx =
       (json_test_ctx_t *) mongoc_apm_command_started_get_context (event);
@@ -304,7 +304,7 @@ started_cb (const mongoc_apm_command_started_t *event)
 
 
 static void
-succeeded_cb (const mongoc_apm_command_succeeded_t *event)
+succeeded_cb (mongoc_apm_command_succeeded_t *event)
 {
    json_test_ctx_t *ctx =
       (json_test_ctx_t *) mongoc_apm_command_succeeded_get_context (event);
@@ -346,7 +346,7 @@ succeeded_cb (const mongoc_apm_command_succeeded_t *event)
 
 
 static void
-failed_cb (const mongoc_apm_command_failed_t *event)
+failed_cb (mongoc_apm_command_failed_t *event)
 {
    json_test_ctx_t *ctx =
       (json_test_ctx_t *) mongoc_apm_command_failed_get_context (event);
diff --git a/src/libmongoc/tests/test-mongoc-bulk.c b/src/libmongoc/tests/test-mongoc-bulk.c
index 27b2ce248..3e2744f76 100644
--- a/src/libmongoc/tests/test-mongoc-bulk.c
+++ b/src/libmongoc/tests/test-mongoc-bulk.c
@@ -3509,7 +3509,7 @@ typedef struct {
 
 
 void
-command_succeeded (const mongoc_apm_command_succeeded_t *event)
+command_succeeded (mongoc_apm_command_succeeded_t *event)
 {
    const char *cmd_name = mongoc_apm_command_succeeded_get_command_name (event);
 
diff --git a/src/libmongoc/tests/test-mongoc-change-stream.c b/src/libmongoc/tests/test-mongoc-change-stream.c
index 9581421ee..c536b9506 100644
--- a/src/libmongoc/tests/test-mongoc-change-stream.c
+++ b/src/libmongoc/tests/test-mongoc-change-stream.c
@@ -251,7 +251,7 @@ typedef struct _test_resume_token_ctx_t {
 } test_resume_token_ctx_t;
 
 static void
-test_resume_token_command_start (const mongoc_apm_command_started_t *event)
+test_resume_token_command_start (mongoc_apm_command_started_t *event)
 {
    const bson_t *cmd = mongoc_apm_command_started_get_command (event);
    const char *cmd_name = mongoc_apm_command_started_get_command_name (event);
@@ -394,7 +394,7 @@ typedef struct _test_batch_size_ctx {
 } test_batch_size_ctx_t;
 
 static void
-test_batch_size_command_succeeded (const mongoc_apm_command_succeeded_t *event)
+test_batch_size_command_succeeded (mongoc_apm_command_succeeded_t *event)
 {
    const bson_t *reply = mongoc_apm_command_succeeded_get_reply (event);
    const char *cmd_name = mongoc_apm_command_succeeded_get_command_name (event);
@@ -1113,7 +1113,7 @@ typedef struct {
 } array_started_ctx_t;
 
 static void
-_accepts_array_started (const mongoc_apm_command_started_t *event)
+_accepts_array_started (mongoc_apm_command_started_t *event)
 {
    const bson_t *cmd = mongoc_apm_command_started_get_command (event);
    const char *cmd_name = mongoc_apm_command_started_get_command_name (event);
@@ -1254,7 +1254,7 @@ typedef struct {
    }
 
 static void
-_resume_at_optime_started (const mongoc_apm_command_started_t *event)
+_resume_at_optime_started (mongoc_apm_command_started_t *event)
 {
    resume_at_optime_ctx_t *ctx;
 
@@ -1283,7 +1283,7 @@ _resume_at_optime_started (const mongoc_apm_command_started_t *event)
 }
 
 static void
-_resume_at_optime_succeeded (const mongoc_apm_command_succeeded_t *event)
+_resume_at_optime_succeeded (mongoc_apm_command_succeeded_t *event)
 {
    resume_at_optime_ctx_t *ctx;
 
diff --git a/src/libmongoc/tests/test-mongoc-client-session.c b/src/libmongoc/tests/test-mongoc-client-session.c
index ed0e99437..6fbaad84d 100644
--- a/src/libmongoc/tests/test-mongoc-client-session.c
+++ b/src/libmongoc/tests/test-mongoc-client-session.c
@@ -510,7 +510,7 @@ typedef struct {
 } endsessions_test_t;
 
 static void
-endsessions_started_cb (const mongoc_apm_command_started_t *event)
+endsessions_started_cb (mongoc_apm_command_started_t *event)
 {
    endsessions_test_t *test;
    bson_t *cmd;
@@ -527,7 +527,7 @@ endsessions_started_cb (const mongoc_apm_command_started_t *event)
 }
 
 static void
-endsessions_succeeded_cb (const mongoc_apm_command_succeeded_t *event)
+endsessions_succeeded_cb (mongoc_apm_command_succeeded_t *event)
 {
    endsessions_test_t *test;
 
@@ -920,7 +920,7 @@ typedef struct {
 
 
 static void
-started (const mongoc_apm_command_started_t *event)
+started (mongoc_apm_command_started_t *event)
 {
    char errmsg[1000];
    match_ctx_t ctx = {errmsg, sizeof (errmsg), false /* strict numbers */};
@@ -1007,7 +1007,7 @@ started (const mongoc_apm_command_started_t *event)
 
 
 static void
-succeeded (const mongoc_apm_command_succeeded_t *event)
+succeeded (mongoc_apm_command_succeeded_t *event)
 {
    bson_iter_t iter;
    bool has_cluster_time;
@@ -1048,7 +1048,7 @@ succeeded (const mongoc_apm_command_succeeded_t *event)
 
 
 static void
-failed (const mongoc_apm_command_failed_t *event)
+failed (mongoc_apm_command_failed_t *event)
 {
    const char *cmd_name;
    bson_error_t error;
@@ -2049,7 +2049,6 @@ _test_bulk (session_test_t *test, mongoc_bulk_operation_t *bulk)
 }
 
 
-
 /* test the standard mongoc_collection_create_bulk_operation_with_opts */
 static void
 test_bulk (session_test_t *test)
@@ -2640,12 +2639,12 @@ test_session_install (TestSuite *suite)
       suite, "/Session/collection_names", test_collection_names, true);
    add_session_test (suite, "/Session/bulk", test_bulk, false);
    add_session_test (suite, "/Session/find_indexes", test_find_indexes, true);
-   TestSuite_AddFull (suite,                                          
+   TestSuite_AddFull (suite,
                       "/Session/bulk_set_session",
                       run_session_test_bulk_operation,
-                      NULL,                                            
+                      NULL,
                       test_bulk_set_session,
-                      test_framework_skip_if_no_cluster_time,          
+                      test_framework_skip_if_no_cluster_time,
                       test_framework_skip_if_no_crypto);
    TestSuite_AddFull (suite,
                       "/Session/bulk_set_client",
diff --git a/src/libmongoc/tests/test-mongoc-cluster.c b/src/libmongoc/tests/test-mongoc-cluster.c
index 646fe9d9f..8b1ee7eb2 100644
--- a/src/libmongoc/tests/test-mongoc-cluster.c
+++ b/src/libmongoc/tests/test-mongoc-cluster.c
@@ -405,7 +405,7 @@ typedef struct {
 
 
 static void
-test_cluster_time_cmd_started_cb (const mongoc_apm_command_started_t *event)
+test_cluster_time_cmd_started_cb (mongoc_apm_command_started_t *event)
 {
    const bson_t *cmd;
    cluster_time_test_t *test;
@@ -454,7 +454,7 @@ test_cluster_time_cmd_started_cb (const mongoc_apm_command_started_t *event)
 
 
 static void
-test_cluster_time_cmd_succeeded_cb (const mongoc_apm_command_succeeded_t *event)
+test_cluster_time_cmd_succeeded_cb (mongoc_apm_command_succeeded_t *event)
 {
    const bson_t *reply;
    cluster_time_test_t *test;
diff --git a/src/libmongoc/tests/test-mongoc-collection.c b/src/libmongoc/tests/test-mongoc-collection.c
index da764a28e..cc69f6a95 100644
--- a/src/libmongoc/tests/test-mongoc-collection.c
+++ b/src/libmongoc/tests/test-mongoc-collection.c
@@ -4858,7 +4858,7 @@ typedef struct {
 
 /* Tests that commands match the `expected_command` in the update ctx */
 void
-_test_crud_command_start (const mongoc_apm_command_started_t *event)
+_test_crud_command_start (mongoc_apm_command_started_t *event)
 {
    const bson_t *cmd = mongoc_apm_command_started_get_command (event);
    const char *cmd_name = mongoc_apm_command_started_get_command_name (event);
diff --git a/src/libmongoc/tests/test-mongoc-command-monitoring.c b/src/libmongoc/tests/test-mongoc-command-monitoring.c
index 389f5e93c..73b79dd90 100644
--- a/src/libmongoc/tests/test-mongoc-command-monitoring.c
+++ b/src/libmongoc/tests/test-mongoc-command-monitoring.c
@@ -103,7 +103,7 @@ test_all_spec_tests (TestSuite *suite)
 
 
 static void
-test_get_error_failed_cb (const mongoc_apm_command_failed_t *event)
+test_get_error_failed_cb (mongoc_apm_command_failed_t *event)
 {
    bson_error_t *error;
 
@@ -165,7 +165,7 @@ insert_200_docs (mongoc_collection_t *collection)
 
 
 static void
-increment (const mongoc_apm_command_started_t *event)
+increment (mongoc_apm_command_started_t *event)
 {
    int *i = (int *) mongoc_apm_command_started_get_context (event);
 
@@ -186,7 +186,7 @@ increment_callbacks (void)
 
 
 static void
-decrement (const mongoc_apm_command_started_t *event)
+decrement (mongoc_apm_command_started_t *event)
 {
    int *i = (int *) mongoc_apm_command_started_get_context (event);
 
@@ -324,7 +324,7 @@ test_reset_callbacks (void)
 
 
 static void
-test_set_callbacks_cb (const mongoc_apm_command_started_t *event)
+test_set_callbacks_cb (mongoc_apm_command_started_t *event)
 {
    int *n_calls = (int *) mongoc_apm_command_started_get_context (event);
 
@@ -445,7 +445,7 @@ op_id_test_cleanup (op_id_test_t *test)
 
 
 static void
-test_op_id_started_cb (const mongoc_apm_command_started_t *event)
+test_op_id_started_cb (mongoc_apm_command_started_t *event)
 {
    op_id_test_t *test;
    ids_t ids;
@@ -461,7 +461,7 @@ test_op_id_started_cb (const mongoc_apm_command_started_t *event)
 
 
 static void
-test_op_id_succeeded_cb (const mongoc_apm_command_succeeded_t *event)
+test_op_id_succeeded_cb (mongoc_apm_command_succeeded_t *event)
 {
    op_id_test_t *test;
    ids_t ids;
@@ -477,7 +477,7 @@ test_op_id_succeeded_cb (const mongoc_apm_command_succeeded_t *event)
 
 
 static void
-test_op_id_failed_cb (const mongoc_apm_command_failed_t *event)
+test_op_id_failed_cb (mongoc_apm_command_failed_t *event)
 {
    op_id_test_t *test;
    ids_t ids;
@@ -760,7 +760,7 @@ cmd_test_cleanup (cmd_test_t *test)
 
 
 static void
-cmd_started_cb (const mongoc_apm_command_started_t *event)
+cmd_started_cb (mongoc_apm_command_started_t *event)
 {
    cmd_test_t *test;
 
@@ -784,7 +784,7 @@ cmd_started_cb (const mongoc_apm_command_started_t *event)
 
 
 static void
-cmd_succeeded_cb (const mongoc_apm_command_succeeded_t *event)
+cmd_succeeded_cb (mongoc_apm_command_succeeded_t *event)
 {
    cmd_test_t *test;
    int64_t duration;
@@ -806,7 +806,7 @@ cmd_succeeded_cb (const mongoc_apm_command_succeeded_t *event)
 
 
 static void
-cmd_failed_cb (const mongoc_apm_command_failed_t *event)
+cmd_failed_cb (mongoc_apm_command_failed_t *event)
 {
    cmd_test_t *test;
    int64_t duration;
@@ -1041,8 +1041,7 @@ cmd_failed_reply_test_cleanup (cmd_failed_reply_test_t *test)
 
 
 static void
-command_failed_reply_command_failed_cb (
-   const mongoc_apm_command_failed_t *event)
+command_failed_reply_command_failed_cb (mongoc_apm_command_failed_t *event)
 {
    cmd_failed_reply_test_t *test;
 
diff --git a/src/libmongoc/tests/test-mongoc-cursor.c b/src/libmongoc/tests/test-mongoc-cursor.c
index 8a9458dcd..95c262467 100644
--- a/src/libmongoc/tests/test-mongoc-cursor.c
+++ b/src/libmongoc/tests/test-mongoc-cursor.c
@@ -211,8 +211,7 @@ typedef struct {
 
 
 static void
-_test_common_server_hint_command_started (
-   const mongoc_apm_command_started_t *event)
+_test_common_server_hint_command_started (mongoc_apm_command_started_t *event)
 {
    const mongoc_host_list_t *host = mongoc_apm_command_started_get_host (event);
    const char *cmd = mongoc_apm_command_started_get_command_name (event);
@@ -579,7 +578,7 @@ typedef struct {
 
 
 static void
-killcursors_succeeded (const mongoc_apm_command_succeeded_t *event)
+killcursors_succeeded (mongoc_apm_command_succeeded_t *event)
 {
    killcursors_test_t *ctx;
    const bson_t *reply;
diff --git a/src/libmongoc/tests/test-mongoc-dns.c b/src/libmongoc/tests/test-mongoc-dns.c
index 014a1d516..6173838ec 100644
--- a/src/libmongoc/tests/test-mongoc-dns.c
+++ b/src/libmongoc/tests/test-mongoc-dns.c
@@ -78,10 +78,10 @@ typedef struct {
 
 
 static void
-topology_changed (const mongoc_apm_topology_changed_t *event)
+topology_changed (mongoc_apm_topology_changed_t *event)
 {
    context_t *ctx;
-   const mongoc_topology_description_t *td;
+   mongoc_topology_description_t *td;
    size_t i;
    size_t n;
    mongoc_server_description_t **sds;
diff --git a/src/libmongoc/tests/test-mongoc-sdam-monitoring.c b/src/libmongoc/tests/test-mongoc-sdam-monitoring.c
index b45a46eef..44c3370cd 100644
--- a/src/libmongoc/tests/test-mongoc-sdam-monitoring.c
+++ b/src/libmongoc/tests/test-mongoc-sdam-monitoring.c
@@ -124,7 +124,7 @@ td_to_bson (const mongoc_topology_description_t *td, bson_t *bson)
 }
 
 static void
-server_changed (const mongoc_apm_server_changed_t *event)
+server_changed (mongoc_apm_server_changed_t *event)
 {
    context_t *ctx;
    bson_oid_t topology_id;
@@ -161,7 +161,7 @@ server_changed (const mongoc_apm_server_changed_t *event)
 }
 
 static void
-server_opening (const mongoc_apm_server_opening_t *event)
+server_opening (mongoc_apm_server_opening_t *event)
 {
    context_t *ctx;
    bson_oid_t topology_id;
@@ -184,7 +184,7 @@ server_opening (const mongoc_apm_server_opening_t *event)
 }
 
 static void
-server_closed (const mongoc_apm_server_closed_t *event)
+server_closed (mongoc_apm_server_closed_t *event)
 {
    context_t *ctx;
    bson_oid_t topology_id;
@@ -207,7 +207,7 @@ server_closed (const mongoc_apm_server_closed_t *event)
 }
 
 static void
-topology_changed (const mongoc_apm_topology_changed_t *event)
+topology_changed (mongoc_apm_topology_changed_t *event)
 {
    context_t *ctx;
    bson_oid_t topology_id;
@@ -240,7 +240,7 @@ topology_changed (const mongoc_apm_topology_changed_t *event)
 }
 
 static void
-topology_opening (const mongoc_apm_topology_opening_t *event)
+topology_opening (mongoc_apm_topology_opening_t *event)
 {
    context_t *ctx;
    bson_oid_t zeroes;
@@ -258,7 +258,7 @@ topology_opening (const mongoc_apm_topology_opening_t *event)
 }
 
 static void
-topology_closed (const mongoc_apm_topology_closed_t *event)
+topology_closed (mongoc_apm_topology_closed_t *event)
 {
    context_t *ctx;
    bson_oid_t topology_id;
@@ -274,7 +274,7 @@ topology_closed (const mongoc_apm_topology_closed_t *event)
 
 /* no standard tests in the specs repo for heartbeat events, so invent some */
 static void
-server_heartbeat_started (const mongoc_apm_server_heartbeat_started_t *event)
+server_heartbeat_started (mongoc_apm_server_heartbeat_started_t *event)
 {
    context_t *ctx;
    const mongoc_host_list_t *host;
@@ -290,8 +290,7 @@ server_heartbeat_started (const mongoc_apm_server_heartbeat_started_t *event)
 }
 
 static void
-server_heartbeat_succeeded (
-   const mongoc_apm_server_heartbeat_succeeded_t *event)
+server_heartbeat_succeeded (mongoc_apm_server_heartbeat_succeeded_t *event)
 {
    context_t *ctx;
    const mongoc_host_list_t *host;
@@ -312,7 +311,7 @@ server_heartbeat_succeeded (
 }
 
 static void
-server_heartbeat_failed (const mongoc_apm_server_heartbeat_failed_t *event)
+server_heartbeat_failed (mongoc_apm_server_heartbeat_failed_t *event)
 {
    context_t *ctx;
    const mongoc_host_list_t *host;
diff --git a/src/libmongoc/tests/test-mongoc-topology-reconcile.c b/src/libmongoc/tests/test-mongoc-topology-reconcile.c
index d8c46f4bc..484e6b00c 100644
--- a/src/libmongoc/tests/test-mongoc-topology-reconcile.c
+++ b/src/libmongoc/tests/test-mongoc-topology-reconcile.c
@@ -334,7 +334,7 @@ typedef struct {
 
 
 static void
-server_opening (const mongoc_apm_server_opening_t *event)
+server_opening (mongoc_apm_server_opening_t *event)
 {
    reconcile_test_data_t *data = (reconcile_test_data_t *) event->context;
 
diff --git a/src/libmongoc/tests/test-mongoc-topology-scanner.c b/src/libmongoc/tests/test-mongoc-topology-scanner.c
index 79bd9671b..f98cd9006 100644
--- a/src/libmongoc/tests/test-mongoc-topology-scanner.c
+++ b/src/libmongoc/tests/test-mongoc-topology-scanner.c
@@ -619,7 +619,7 @@ test_topology_retired_fails_to_initiate (void)
 }
 
 static void
-heartbeat_failed (const mongoc_apm_server_heartbeat_failed_t *event)
+heartbeat_failed (mongoc_apm_server_heartbeat_failed_t *event)
 {
    bson_error_t error;
    bool *failed =
diff --git a/src/libmongoc/tests/test-mongoc-topology.c b/src/libmongoc/tests/test-mongoc-topology.c
index d1ca7cf11..b5211c810 100644
--- a/src/libmongoc/tests/test-mongoc-topology.c
+++ b/src/libmongoc/tests/test-mongoc-topology.c
@@ -1148,7 +1148,7 @@ typedef struct {
 
 
 static void
-check_started (const mongoc_apm_server_heartbeat_started_t *event)
+check_started (mongoc_apm_server_heartbeat_started_t *event)
 {
    checks_t *c;
 
@@ -1158,7 +1158,7 @@ check_started (const mongoc_apm_server_heartbeat_started_t *event)
 
 
 static void
-check_succeeded (const mongoc_apm_server_heartbeat_succeeded_t *event)
+check_succeeded (mongoc_apm_server_heartbeat_succeeded_t *event)
 {
    checks_t *c;
 
@@ -1168,7 +1168,7 @@ check_succeeded (const mongoc_apm_server_heartbeat_succeeded_t *event)
 
 
 static void
-check_failed (const mongoc_apm_server_heartbeat_failed_t *event)
+check_failed (mongoc_apm_server_heartbeat_failed_t *event)
 {
    checks_t *c;
 
@@ -1651,7 +1651,7 @@ typedef struct {
 } request_scan_error_ctx_t;
 
 static void
-_server_changed (const mongoc_apm_server_changed_t *event)
+_server_changed (mongoc_apm_server_changed_t *event)
 {
    const mongoc_server_description_t *sd;
    request_scan_error_ctx_t *ctx;
diff --git a/src/libmongoc/tests/test-mongoc-write-commands.c b/src/libmongoc/tests/test-mongoc-write-commands.c
index 47aecdec4..0bbee5d68 100644
--- a/src/libmongoc/tests/test-mongoc-write-commands.c
+++ b/src/libmongoc/tests/test-mongoc-write-commands.c
@@ -274,7 +274,7 @@ test_bypass_validation (void *context)
 }
 
 static void
-test_bypass_command_started (const mongoc_apm_command_started_t *event)
+test_bypass_command_started (mongoc_apm_command_started_t *event)
 {
    ASSERT_HAS_NOT_FIELD (mongoc_apm_command_started_get_command (event),
                          "bypassDocumentValidation");