diff --git a/cpp/Testable.h b/cpp/Testable.h
index 4b4e7db9a..bc5c290dc 100644
--- a/cpp/Testable.h
+++ b/cpp/Testable.h
@@ -11,7 +11,7 @@
 #include <boost/shared_ptr.hpp>
 #include <stdio.h>
 
-#define GTSAM_PRINT(x)(x.print(#x))
+#define GTSAM_PRINT(x)((x).print(#x))
 
 namespace gtsam {