diff --git a/src/window.c b/src/window.c
index 5f5bb2a..ee9ef9c 100644
--- a/src/window.c
+++ b/src/window.c
@@ -4273,7 +4273,7 @@
     win_T	*wp;
 {
     wp->w_lines_valid = 0;
-    wp->w_lines = (wline_T *)alloc((unsigned)(Rows * sizeof(wline_T)));
+    wp->w_lines = (wline_T *)alloc_clear((unsigned)(Rows * sizeof(wline_T)));
     if (wp->w_lines == NULL)
 	return FAIL;
     return OK;