diff --git a/src/mongo/bson/bsontypes.h b/src/mongo/bson/bsontypes.h
index 50588789dc..8936d44c6d 100644
--- a/src/mongo/bson/bsontypes.h
+++ b/src/mongo/bson/bsontypes.h
@@ -212,49 +212,36 @@ bool isValidBinDataType(int type);
  *  Note: if the order changes, indexes have to be re-built or than can be corruption
  */
 inline int canonicalizeBSONType(BSONType type) {
-    switch (type) {
-        case MinKey:
-        case MaxKey:
-            return type;
-        case EOO:
-        case Undefined:
-            return 0;
-        case jstNULL:
-            return 5;
-        case NumberDecimal:
-        case NumberDouble:
-        case NumberInt:
-        case NumberLong:
-            return 10;
-        case mongo::String:
-        case Symbol:
-            return 15;
-        case Object:
-            return 20;
-        case mongo::Array:
-            return 25;
-        case BinData:
-            return 30;
-        case jstOID:
-            return 35;
-        case mongo::Bool:
-            return 40;
-        case mongo::Date:
-            return 45;
-        case bsonTimestamp:
-            return 47;
-        case RegEx:
-            return 50;
-        case DBRef:
-            return 55;
-        case Code:
-            return 60;
-        case CodeWScope:
-            return 65;
-        default:
-            verify(0);
-            return -1;
-    }
+    constexpr static auto mapper = [] {
+        auto out = std::array<int8_t, 256>();  // Value-init everything to 0 by default.
+        out[uint8_t(MinKey)] = MinKey;
+        out[uint8_t(MaxKey)] = MaxKey;
+        out[uint8_t(EOO)] =            //
+            out[uint8_t(Undefined)] =  //
+            0;
+        out[uint8_t(jstNULL)] = 5;
+        out[uint8_t(NumberDecimal)] =     //
+            out[uint8_t(NumberDouble)] =  //
+            out[uint8_t(NumberInt)] =     //
+            out[uint8_t(NumberLong)] =    //
+            10;
+        out[uint8_t(mongo::String)] =  //
+            out[uint8_t(Symbol)] =     //
+            15;
+        out[uint8_t(Object)] = 20;
+        out[uint8_t(mongo::Array)] = 25;
+        out[uint8_t(BinData)] = 30;
+        out[uint8_t(jstOID)] = 35;
+        out[uint8_t(mongo::Bool)] = 40;
+        out[uint8_t(mongo::Date)] = 45;
+        out[uint8_t(bsonTimestamp)] = 47;
+        out[uint8_t(RegEx)] = 50;
+        out[uint8_t(DBRef)] = 55;
+        out[uint8_t(Code)] = 60;
+        out[uint8_t(CodeWScope)] = 65;
+        return out;
+    }();
+    return mapper[uint8_t(type)];
 }
 
 template <BSONType value>