diff --git a/src/mdlib.c b/src/mdlib.c
index 1e7613a47..b31d39623 100644
--- a/src/mdlib.c
+++ b/src/mdlib.c
@@ -839,7 +839,7 @@ do_runtime_info(int *rtcontext)
 }
 
 void
-release_runtime_info()
+release_runtime_info(void)
 {
     while (idxopttext > 0) {
         --idxopttext;