1 files changed, 15 insertions, 3 deletions
diff --git a/spec/ruby/core/array/pack/c_spec.rb b/spec/ruby/core/array/pack/c_spec.rb
index 7200830331..47b71b663d 100644
--- a/spec/ruby/core/array/pack/c_spec.rb
+++ b/spec/ruby/core/array/pack/c_spec.rb
@@ -1,4 +1,4 @@
-# -*- encoding: binary -*-
+# encoding: binary
 
 require_relative '../../../spec_helper'
 require_relative '../fixtures/classes'
@@ -45,8 +45,20 @@ describe :array_pack_8bit, shared: true do
     [1, 2, 3, 4, 5].pack(pack_format('*')).should == "\x01\x02\x03\x04\x05"
   end
 
-  it "ignores NULL bytes between directives" do
-    [1, 2, 3].pack(pack_format("\000", 2)).should == "\x01\x02"
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      suppress_warning do
+        [1, 2, 3].pack(pack_format("\000", 2)).should == "\x01\x02"
+      end
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        [1, 2, 3].pack(pack_format("\000", 2))
+      }.should raise_error(ArgumentError, /unknown pack directive/)
+    end
   end
 
   it "ignores spaces between directives" do