diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 20d625a..8148703 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -351,4 +351,6 @@
 	return asprintf_expr_inout_ints(var, false, nints, ints);
 }
 
+int get_stack_size(const char *str, unsigned long *_size);
+
 #endif /* GIT_COMPAT_UTIL_H */