--- trackballs/src/general.h
+++ trackballs/src/general.h
@@ -57,9 +57,10 @@
 #endif
 
 
-#undef SHARE_DIR
 extern char effectiveShareDir[];
+#ifndef SHARE_DIR
 #define SHARE_DIR effectiveShareDir
+#endif
 
 //#define SHARE_DIR "/home/matbr/development/trackballs/share"
 //#define SHARE_DIR "./share/trackballs"