diff --git a/src/physfs_internal.h b/src/physfs_internal.h
index f8716f8..6aceff1 100644
--- a/src/physfs_internal.h
+++ b/src/physfs_internal.h
@@ -26,7 +26,7 @@
 #include <assert.h>
 
 /* !!! FIXME: remove this when revamping stack allocation code... */
-#if defined(_MSC_VER) || defined(__MINGW32__)
+#if defined(_MSC_VER) || defined(__MINGW32__) || defined(__WATCOMC__)
 #include <malloc.h>
 #endif