--- lesstif2-0.94.4.orig/include/Motif-2.1/Xm/XmStrDefs.h
+++ lesstif2-0.94.4/include/Motif-2.1/Xm/XmStrDefs.h
@@ -28,6 +28,8 @@
 
 #include <X11/StringDefs.h>
 
+#include <Xm/Xm.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
