diff --git a/package_release.py b/package_release.py
index 5660fdb8d81a87e00caa02275d8c90b7c861001d..36dde3c47b55218b095297dfa28280ba96c02205 100755
--- a/package_release.py
+++ b/package_release.py
@@ -69,7 +69,7 @@ def main():
         shutil.copyfile(source_file, target_file, follow_symlinks=True)
 
     # Handle SDK if available
-    if args.sdk_dir is not "":
+    if args.sdk_dir != "":
         sdkfile = "{}.sh".format(sdkname)
         sdkfilepath = "{}/{}".format(args.sdk_dir, sdkfile)
         sdkoutput_dir = "{}/sdk".format(output_dir)