diff --git a/test/irb/test_context.rb b/test/irb/test_context.rb
index 4d256a73a..0d41cc03a 100644
--- a/test/irb/test_context.rb
+++ b/test/irb/test_context.rb
@@ -50,9 +50,9 @@ def test_evaluate_with_exception
     end
 
     def test_evaluate_with_encoding_error_without_lineno
-      pend if RUBY_ENGINE == 'truffleruby'
-      assert_raise_with_message(EncodingError, /invalid symbol/) {
-        @context.evaluate(%q[{"\xAE": 1}], 1)
+      # TruffleRuby adds 'encoding' in the middle of the message
+      assert_raise_with_message(EncodingError, /invalid( encoding)? symbol/) {
+        @context.evaluate(%q[:"\xAE"], 1)
         # The backtrace of this invalid encoding hash doesn't contain lineno.
       }
     end