diff --git a/babeld/babeld.c b/babeld/babeld.c
index 1ae3f04..eaa91b7 100644
--- a/babeld/babeld.c
+++ b/babeld/babeld.c
@@ -328,8 +328,8 @@
         /* if there is no timeout, we must wait. */
         if(timeval_compare(&tv, &babel_now) > 0) {
             timeval_minus(&tv, &tv, &babel_now);
-            debugf(BABEL_DEBUG_TIMEOUT, "babel main loop : timeout: %ld msecs",
-                   tv.tv_sec * 1000 + tv.tv_usec / 1000);
+            debugf(BABEL_DEBUG_TIMEOUT, "babel main loop : timeout: %lld msecs",
+                   tv.tv_sec * 1000LL + tv.tv_usec / 1000LL);
             /* it happens often to have less than 1 ms, it's bad. */
             timeval_add_msec(&tv, &tv, 300);
             babel_set_timer(&tv);