diff --git a/fsmonitor-ipc.c b/fsmonitor-ipc.c
index e62901a85b..a629d34a11 100644
--- a/fsmonitor-ipc.c
+++ b/fsmonitor-ipc.c
@@ -53,7 +53,7 @@ try_again:
 	switch (state) {
 	case IPC_STATE__LISTENING:
 		ret = ipc_client_send_command_to_connection(
-			connection, since_token, strlen(since_token), answer);
+			connection, since_token, since_token ? strlen(since_token) : 0, answer);
 		ipc_client_close_connection(connection);
 
 		trace2_data_intmax("fsm_client", NULL,