diff --git a/src/_macosx.m b/src/_macosx.m
index 66c8c7d389ca..7c34c3d9ca19 100644
--- a/src/_macosx.m
+++ b/src/_macosx.m
@@ -1971,6 +1971,9 @@ - (void)launch:(NSNotification*)notification
     CFMachPortRef port;
     CFRunLoopSourceRef source;
     NSDictionary* dictionary = [notification userInfo];
+    if (! [[dictionary valueForKey:@"NSApplicationName"]
+           isEqualToString:@"Python"])
+        return;
     NSNumber* psnLow = [dictionary valueForKey: @"NSApplicationProcessSerialNumberLow"];
     NSNumber* psnHigh = [dictionary valueForKey: @"NSApplicationProcessSerialNumberHigh"];
     ProcessSerialNumber psn;