diff --git a/service/s3/validators.go b/service/s3/validators.go
index 47bbc2b238b..dcfc386ab05 100644
--- a/service/s3/validators.go
+++ b/service/s3/validators.go
@@ -5966,7 +5966,7 @@ func validateOpPutObjectInput(v *PutObjectInput) error {
 		return nil
 	}
 	invalidParams := smithy.InvalidParamsError{Context: "PutObjectInput"}
-	if v.Bucket == nil {
+	if v.Bucket == nil || *v.Bucket == "" {
 		invalidParams.Add(smithy.NewErrParamRequired("Bucket"))
 	}
 	if v.Key == nil {