diff --git a/libs/pbd/pbd/crossthread.h b/libs/pbd/pbd/crossthread.h
index f9845eedf0..f16cab9405 100644
--- a/libs/pbd/pbd/crossthread.h
+++ b/libs/pbd/pbd/crossthread.h
@@ -20,6 +20,10 @@
 #ifndef __pbd__crossthread_h__
 #define __pbd__crossthread_h__
 
+#ifdef check
+#undef check
+#endif
+
 #include <glibmm/main.h>
 
 class CrossThreadChannel {