diff --git a/libgimpbase/gimpreloc.c b/libgimpbase/gimpreloc.c
index b9fa4df..8cd72f9 100644
--- a/libgimpbase/gimpreloc.c
+++ b/libgimpbase/gimpreloc.c
@@ -27,6 +27,9 @@
 
 #include "gimpreloc.h"
 
+#ifndef PATH_MAX
+#define PATH_MAX 4096
+#endif
 
 /*
  * Find the canonical filename of the executable. Returns the filename