diff --git a/CHANGELOG b/CHANGELOG
index aac07c9..4589740 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,7 @@
+=== master
+
+* Raise ArgumentError if Warning.process is passed non-String as first argument (splattael) (#17, #19)
+
 === 1.2.1 (2021-10-04)
 
 * Recognize additional void context warnings (kachick) (#13)
diff --git a/lib/warning.rb b/lib/warning.rb
index a279a5d..89eb919 100644
--- a/lib/warning.rb
+++ b/lib/warning.rb
@@ -145,7 +145,7 @@ def ignore(regexp, path='')
     #   Warning.process(__FILE__, :missing_ivar=>:backtrace, :keyword_separation=>:raise)
     def process(path='', actions=nil, &block)
       unless path.is_a?(String)
-        raise ArgumentError, "path must be a String not a #{path.class}"
+        raise ArgumentError, "path must be a String (given an instance of #{path.class})"
       end
 
       if block
diff --git a/test/test_warning.rb b/test/test_warning.rb
index c6642a3..6e12547 100644
--- a/test/test_warning.rb
+++ b/test/test_warning.rb
@@ -547,7 +547,7 @@ def test_warning_process_path_no_string
     e = assert_raises(ArgumentError) do
       Warning.process(/foo/) { :raise }
     end
-    assert_includes(e.message, "path must be a String not a Regexp")
+    assert_includes(e.message, "path must be a String (given an instance of Regexp)")
   end
 
   if RUBY_VERSION >= '3.0'