diff --git a/src/eval.c b/src/eval.c
index 78513a2..4e6c7b6 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -8065,6 +8065,7 @@
 # endif
 	++winnr;
     }
+    ga_append(&ga, NUL);
 
     retvar->var_val.var_string = ga.ga_data;
 #else