diff --git a/src/testdir/Make_ming.mak b/src/testdir/Make_ming.mak
index 2ad34b9..671caa2 100644
--- a/src/testdir/Make_ming.mak
+++ b/src/testdir/Make_ming.mak
@@ -138,5 +138,5 @@
 
 test_options.res test_alot.res: opt_test.vim
 
-opt_test.vim: ../option.c gen_opt_test.vim
-	$(VIMPROG) -u NONE -S gen_opt_test.vim --noplugin --not-a-term ../option.c
+opt_test.vim: ../optiondefs.h gen_opt_test.vim
+	$(VIMPROG) -u NONE -S gen_opt_test.vim --noplugin --not-a-term ../optiondefs.h