diff --git a/tests/main.c b/tests/main.c
index 5e7bdcb..5396c7d 100644
--- a/tests/main.c
+++ b/tests/main.c
@@ -52,7 +52,7 @@
 }
 
 static int timer_count;
-int
+static int
 test_timer (struct thread *thread)
 {
   int *count = THREAD_ARG(thread);