diff --git a/src/gtk/app.cpp b/src/gtk/app.cpp
index 6e324b8a47..b784e9d0b9 100644
--- a/src/gtk/app.cpp
+++ b/src/gtk/app.cpp
@@ -791,7 +791,8 @@ int wxEntryStart( int& argc, char *argv[] )
     }
     else
     {
-        g_thread_init(NULL);
+        if (!g_thread_supported())
+            g_thread_init(NULL);
     }
 #endif
 
diff --git a/src/gtk1/app.cpp b/src/gtk1/app.cpp
index 6e324b8a47..b784e9d0b9 100644
--- a/src/gtk1/app.cpp
+++ b/src/gtk1/app.cpp
@@ -791,7 +791,8 @@ int wxEntryStart( int& argc, char *argv[] )
     }
     else
     {
-        g_thread_init(NULL);
+        if (!g_thread_supported())
+            g_thread_init(NULL);
     }
 #endif