diff --git a/src/ops.c b/src/ops.c
index 0f42dea..5c58e52 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -396,7 +396,10 @@
 	return;
 
     /* total is number of screen columns to be inserted/removed */
-    total = amount * p_sw;
+    total = (int)((unsigned)amount * (unsigned)p_sw);
+    if ((total / p_sw) != amount)
+	return; /* multiplication overflow */
+
     oldp = ml_get_curline();
 
     if (!left)