diff --git a/src/rsrv/caservertask.c b/src/rsrv/caservertask.c
index 71b129cde..19822babc 100644
--- a/src/rsrv/caservertask.c
+++ b/src/rsrv/caservertask.c
@@ -477,6 +477,10 @@ void epicsShareAPI casr (unsigned level)
     size_t bytes_reserved;
     struct client *client;
 
+    if ( ! clientQlock ) {
+        return;
+    }
+
     printf ("Channel Access Server V%d.%d\n",
         CA_PROTOCOL_VERSION, CA_MINOR_VERSION);