diff --git a/src/proto/misc1.pro b/src/proto/misc1.pro
index c602b0e..e76bf75 100644
--- a/src/proto/misc1.pro
+++ b/src/proto/misc1.pro
@@ -55,5 +55,5 @@
 void may_trigger_modechanged(void);
 int vim_append_digit_int(int *value, int digit);
 int vim_append_digit_long(long *value, int digit);
-int trim_to_int(long long x);
+int trim_to_int(vimlong_T x);
 /* vim: set ft=c : */