diff --git a/db/repl.cpp b/db/repl.cpp
index 2222831..990b46e 100644
--- a/db/repl.cpp
+++ b/db/repl.cpp
@@ -292,7 +292,10 @@ namespace mongo {
             }
         }
         else {
-            result.append("ismaster", replSettings.slave ? 0 : 1);
+            // if running with --master --slave, ismaster should be 1.
+            // therefore, need to set flag by using replSetting.master instead
+            // of replSetting.slave.
+            result.append("ismaster", replSettings.master ? 1 : 0);
             result.append("msg", "not paired");
         }