diff --git a/script/user_nodefs.h b/script/user_nodefs.h
index f890511f4..3d25d92ec 100644
--- a/script/user_nodefs.h
+++ b/script/user_nodefs.h
@@ -23,3 +23,5 @@
 	if (GIT_MULTIPLY_SIZET_OVERFLOW(out, nelem, elsize)) { __coverity_panic__(); }
 
 #nodef GITERR_CHECK_VERSION(S,V,N) if (giterr__check_version(S,V,N) < 0)  { __coverity_panic__(); }
+
+#nodef LOOKS_LIKE_DRIVE_PREFIX(S) (strlen(S) >= 2 && git__isalpha((S)[0]) && (S)[1] == ':')