diff --git a/libs/pbd/pbd/localtime_r.h b/libs/pbd/pbd/localtime_r.h
index 1e810ec084..532bb3ed12 100644
--- a/libs/pbd/pbd/localtime_r.h
+++ b/libs/pbd/pbd/localtime_r.h
@@ -9,7 +9,7 @@
 
 #elif defined __MINGW64__
 
-#  ifdef (localtime_r)
+#  ifdef localtime_r
 #  undef localtime_r
 #  endif