diff --git a/src/evalfunc.c b/src/evalfunc.c
index 906fa39..7dd5c2a 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -12429,7 +12429,7 @@
 	free_callback(callback, partial);
     else
     {
-	if (timer->tr_partial == NULL)
+	if (partial == NULL)
 	    timer->tr_callback = vim_strsave(callback);
 	else
 	    /* pointer into the partial */