diff --git a/src/cmd/compile/internal/ssa/rewrite.go b/src/cmd/compile/internal/ssa/rewrite.go
index ed5bce861e..17d7cb3414 100644
--- a/src/cmd/compile/internal/ssa/rewrite.go
+++ b/src/cmd/compile/internal/ssa/rewrite.go
@@ -542,7 +542,7 @@ func disjoint(p1 *Value, n1 int64, p2 *Value, n2 int64) bool {
 	}
 	baseAndOffset := func(ptr *Value) (base *Value, offset int64) {
 		base, offset = ptr, 0
-		if base.Op == OpOffPtr {
+		for base.Op == OpOffPtr {
 			offset += base.AuxInt
 			base = base.Args[0]
 		}