diff --git a/lib/error_highlight/core_ext.rb b/lib/error_highlight/core_ext.rb
index 1cfc331..c3354f4 100644
--- a/lib/error_highlight/core_ext.rb
+++ b/lib/error_highlight/core_ext.rb
@@ -24,7 +24,7 @@ module CoreExt
               _, _, snippet, highlight = ErrorHighlight.formatter.message_for(spot).lines
               out += "\n    | #{ snippet }      #{ highlight }"
             else
-              out += "\n    (cannot highlight method definition; try Ruby 4.0 or later)"
+              # do nothing
             end
           end
           ret << "\n" + out if out
diff --git a/test/test_error_highlight.rb b/test/test_error_highlight.rb
index d3ca990..ec39b1c 100644
--- a/test/test_error_highlight.rb
+++ b/test/test_error_highlight.rb
@@ -1450,26 +1450,28 @@ def exc.backtrace_locations = []
       RubyVM::AbstractSyntaxTree.node_id_for_backtrace_location(exc.backtrace_locations.first)
   end
 
-  WRONG_NUMBER_OF_ARGUMENTS_LIENO = __LINE__ + 1
+  def process_callee_snippet(str)
+    return str if MethodDefLocationSupported
+
+    str.sub(/\n +\|.*\n +\^+\n\z/, "")
+  end
+
+  WRONG_NUMBER_OF_ARGUMENTS_LINENO = __LINE__ + 1
   def wrong_number_of_arguments_test(x, y)
     x + y
   end
 
   def test_wrong_number_of_arguments_for_method
     lineno = __LINE__
-    assert_error_message(ArgumentError, <<~END) do
+    assert_error_message(ArgumentError, process_callee_snippet(<<~END)) do
 wrong number of arguments (given 1, expected 2) (ArgumentError)
 
-    caller: #{ __FILE__ }:#{ lineno + 16 }
+    caller: #{ __FILE__ }:#{ lineno + 12 }
     |       wrong_number_of_arguments_test(1)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-    callee: #{ __FILE__ }:#{ WRONG_NUMBER_OF_ARGUMENTS_LIENO }
-    #{
-      MethodDefLocationSupported ?
-   "|   def wrong_number_of_arguments_test(x, y)
-            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^" :
-   "(cannot highlight method definition; try Ruby 4.0 or later)"
-   }
+    callee: #{ __FILE__ }:#{ WRONG_NUMBER_OF_ARGUMENTS_LINENO }
+    |   def wrong_number_of_arguments_test(x, y)
+            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     END
 
       wrong_number_of_arguments_test(1)
@@ -1483,19 +1485,15 @@ def keyword_test(kw1:, kw2:, kw3:)
 
   def test_missing_keyword
     lineno = __LINE__
-    assert_error_message(ArgumentError, <<~END) do
+    assert_error_message(ArgumentError, process_callee_snippet(<<~END)) do
 missing keyword: :kw3 (ArgumentError)
 
-    caller: #{ __FILE__ }:#{ lineno + 16 }
+    caller: #{ __FILE__ }:#{ lineno + 12 }
     |       keyword_test(kw1: 1, kw2: 2)
             ^^^^^^^^^^^^
     callee: #{ __FILE__ }:#{ KEYWORD_TEST_LINENO }
-    #{
-      MethodDefLocationSupported ?
-   "|   def keyword_test(kw1:, kw2:, kw3:)
-            ^^^^^^^^^^^^" :
-   "(cannot highlight method definition; try Ruby 4.0 or later)"
-   }
+    |   def keyword_test(kw1:, kw2:, kw3:)
+            ^^^^^^^^^^^^
     END
 
       keyword_test(kw1: 1, kw2: 2)
@@ -1504,19 +1502,15 @@ def test_missing_keyword
 
   def test_missing_keywords # multiple missing keywords
     lineno = __LINE__
-    assert_error_message(ArgumentError, <<~END) do
+    assert_error_message(ArgumentError, process_callee_snippet(<<~END)) do
 missing keywords: :kw2, :kw3 (ArgumentError)
 
-    caller: #{ __FILE__ }:#{ lineno + 16 }
+    caller: #{ __FILE__ }:#{ lineno + 12 }
     |       keyword_test(kw1: 1)
             ^^^^^^^^^^^^
     callee: #{ __FILE__ }:#{ KEYWORD_TEST_LINENO }
-    #{
-      MethodDefLocationSupported ?
-   "|   def keyword_test(kw1:, kw2:, kw3:)
-            ^^^^^^^^^^^^" :
-   "(cannot highlight method definition; try Ruby 4.0 or later)"
-   }
+    |   def keyword_test(kw1:, kw2:, kw3:)
+            ^^^^^^^^^^^^
     END
 
       keyword_test(kw1: 1)
@@ -1525,19 +1519,15 @@ def test_missing_keywords # multiple missing keywords
 
   def test_unknown_keyword
     lineno = __LINE__
-    assert_error_message(ArgumentError, <<~END) do
+    assert_error_message(ArgumentError, process_callee_snippet(<<~END)) do
 unknown keyword: :kw4 (ArgumentError)
 
-    caller: #{ __FILE__ }:#{ lineno + 16 }
+    caller: #{ __FILE__ }:#{ lineno + 12 }
     |       keyword_test(kw1: 1, kw2: 2, kw3: 3, kw4: 4)
             ^^^^^^^^^^^^
     callee: #{ __FILE__ }:#{ KEYWORD_TEST_LINENO }
-    #{
-      MethodDefLocationSupported ?
-   "|   def keyword_test(kw1:, kw2:, kw3:)
-            ^^^^^^^^^^^^" :
-   "(cannot highlight method definition; try Ruby 4.0 or later)"
-   }
+    |   def keyword_test(kw1:, kw2:, kw3:)
+            ^^^^^^^^^^^^
     END
 
       keyword_test(kw1: 1, kw2: 2, kw3: 3, kw4: 4)
@@ -1546,19 +1536,15 @@ def test_unknown_keyword
 
   def test_unknown_keywords
     lineno = __LINE__
-    assert_error_message(ArgumentError, <<~END) do
+    assert_error_message(ArgumentError, process_callee_snippet(<<~END)) do
 unknown keywords: :kw4, :kw5 (ArgumentError)
 
-    caller: #{ __FILE__ }:#{ lineno + 16 }
+    caller: #{ __FILE__ }:#{ lineno + 12 }
     |       keyword_test(kw1: 1, kw2: 2, kw3: 3, kw4: 4, kw5: 5)
             ^^^^^^^^^^^^
     callee: #{ __FILE__ }:#{ KEYWORD_TEST_LINENO }
-    #{
-      MethodDefLocationSupported ?
-   "|   def keyword_test(kw1:, kw2:, kw3:)
-            ^^^^^^^^^^^^" :
-   "(cannot highlight method definition; try Ruby 4.0 or later)"
-   }
+    |   def keyword_test(kw1:, kw2:, kw3:)
+            ^^^^^^^^^^^^
     END
 
       keyword_test(kw1: 1, kw2: 2, kw3: 3, kw4: 4, kw5: 5)
@@ -1576,19 +1562,15 @@ def wrong_number_of_arguments_test2(
 
   def test_wrong_number_of_arguments_for_method2
     lineno = __LINE__
-    assert_error_message(ArgumentError, <<~END) do
+    assert_error_message(ArgumentError, process_callee_snippet(<<~END)) do
 wrong number of arguments (given 1, expected 3) (ArgumentError)
 
-    caller: #{ __FILE__ }:#{ lineno + 16 }
+    caller: #{ __FILE__ }:#{ lineno + 12 }
     |       wrong_number_of_arguments_test2(1)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     callee: #{ __FILE__ }:#{ WRONG_NUBMER_OF_ARGUMENTS_TEST2_LINENO }
-    #{
-      MethodDefLocationSupported ?
-   "|   def wrong_number_of_arguments_test2(
-            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^" :
-   "(cannot highlight method definition; try Ruby 4.0 or later)"
-   }
+    |   def wrong_number_of_arguments_test2(
+            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     END
 
       wrong_number_of_arguments_test2(1)
@@ -1598,19 +1580,15 @@ def test_wrong_number_of_arguments_for_method2
   def test_wrong_number_of_arguments_for_lambda_literal
     v = -> {}
     lineno = __LINE__
-    assert_error_message(ArgumentError, <<~END) do
+    assert_error_message(ArgumentError, process_callee_snippet(<<~END)) do
 wrong number of arguments (given 1, expected 0) (ArgumentError)
 
-    caller: #{ __FILE__ }:#{ lineno + 16 }
+    caller: #{ __FILE__ }:#{ lineno + 12 }
     |       v.call(1)
              ^^^^^
     callee: #{ __FILE__ }:#{ lineno - 1 }
-    #{
-      MethodDefLocationSupported ?
-   "|     v = -> {}
-              ^^" :
-   "(cannot highlight method definition; try Ruby 4.0 or later)"
-   }
+    |     v = -> {}
+              ^^
     END
 
       v.call(1)
@@ -1620,19 +1598,15 @@ def test_wrong_number_of_arguments_for_lambda_literal
   def test_wrong_number_of_arguments_for_lambda_method
     v = lambda { }
     lineno = __LINE__
-    assert_error_message(ArgumentError, <<~END) do
+    assert_error_message(ArgumentError, process_callee_snippet(<<~END)) do
 wrong number of arguments (given 1, expected 0) (ArgumentError)
 
-    caller: #{ __FILE__ }:#{ lineno + 16 }
+    caller: #{ __FILE__ }:#{ lineno + 12 }
     |       v.call(1)
              ^^^^^
     callee: #{ __FILE__ }:#{ lineno - 1 }
-    #{
-      MethodDefLocationSupported ?
-   "|     v = lambda { }
-                     ^" :
-   "(cannot highlight method definition; try Ruby 4.0 or later)"
-   }
+    |     v = lambda { }
+                     ^
     END
 
       v.call(1)
@@ -1646,19 +1620,15 @@ def test_wrong_number_of_arguments_for_lambda_method
 
   def test_wrong_number_of_arguments_for_define_method
     lineno = __LINE__
-    assert_error_message(ArgumentError, <<~END) do
+    assert_error_message(ArgumentError, process_callee_snippet(<<~END)) do
 wrong number of arguments (given 1, expected 2) (ArgumentError)
 
-    caller: #{ __FILE__ }:#{ lineno + 16 }
+    caller: #{ __FILE__ }:#{ lineno + 12 }
     |       define_method_test(1)
             ^^^^^^^^^^^^^^^^^^
     callee: #{ __FILE__ }:#{ DEFINE_METHOD_TEST_LINENO }
-    #{
-      MethodDefLocationSupported ?
-   "|   define_method :define_method_test do |x, y|
-                                          ^^" :
-   "(cannot highlight method definition; try Ruby 4.0 or later)"
-   }
+    |   define_method :define_method_test do |x, y|
+                                          ^^
     END
 
       define_method_test(1)
@@ -1742,19 +1712,15 @@ def self . baz(x:)
 
   def test_singleton_method_with_spacing_missing_keyword
     lineno = __LINE__
-    assert_error_message(ArgumentError, <<~END) do
+    assert_error_message(ArgumentError, process_callee_snippet(<<~END)) do
 missing keyword: :x (ArgumentError)
 
-    caller: #{ __FILE__ }:#{ lineno + 16 }
+    caller: #{ __FILE__ }:#{ lineno + 12 }
     |       SingletonMethodWithSpacing.baz
                                       ^^^^
     callee: #{ __FILE__ }:#{ SingletonMethodWithSpacing::LINENO }
-    #{
-      MethodDefLocationSupported ?
-   "|     def self . baz(x:)
-                   ^^^^^" :
-   "(cannot highlight method definition; try Ruby 4.0 or later)"
-   }
+    |     def self . baz(x:)
+                   ^^^^^
     END
 
       SingletonMethodWithSpacing.baz
@@ -1770,19 +1736,15 @@ def self.run(shop_id:, param1:)
 
   def test_singleton_method_multiple_missing_keywords
     lineno = __LINE__
-    assert_error_message(ArgumentError, <<~END) do
+    assert_error_message(ArgumentError, process_callee_snippet(<<~END)) do
 missing keywords: :shop_id, :param1 (ArgumentError)
 
-    caller: #{ __FILE__ }:#{ lineno + 16 }
+    caller: #{ __FILE__ }:#{ lineno + 12 }
     |       SingletonMethodMultipleKwargs.run
                                          ^^^^
     callee: #{ __FILE__ }:#{ SingletonMethodMultipleKwargs::LINENO }
-    #{
-      MethodDefLocationSupported ?
-   "|     def self.run(shop_id:, param1:)
-                  ^^^^" :
-   "(cannot highlight method definition; try Ruby 4.0 or later)"
-   }
+    |     def self.run(shop_id:, param1:)
+                  ^^^^
     END
 
       SingletonMethodMultipleKwargs.run