diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 759f5bb968..a5eb995a60 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -2324,7 +2324,7 @@ cleanup:
         int rc;
 
         if ((rc = virPidFileReadPath(pidfile, &pid)) < 0) {
-            VIR_DEBUG("Failed to read pidfile %s: %d",
+            VIR_DEBUG("Failed to read pidfile %s: %s",
                       pidfile, virStrerror(-rc, ebuf, sizeof(ebuf)));
         } else {
             VIR_DEBUG("Killing QMP caps process %lld", (long long) pid);