diff --git a/aider/coders/editblock_coder.py b/aider/coders/editblock_coder.py
index bb0a01914..d8f85da52 100644
--- a/aider/coders/editblock_coder.py
+++ b/aider/coders/editblock_coder.py
@@ -414,11 +414,15 @@ def strip_filename(filename, fence):
     start_fence = fence[0]
     if filename.startswith(start_fence):
         candidate = filename[len(start_fence) :]
-        if candidate and "." in candidate:
+        if candidate and ("." in candidate or "/" in candidate):
             return candidate
+        return
 
     if filename.startswith(triple_backticks):
-        filename = filename[len(triple_backticks) :]
+        candidate = filename[len(triple_backticks) :]
+        if candidate and ("." in candidate or "/" in candidate):
+            return candidate
+        return
 
     filename = filename.rstrip(":")
     filename = filename.lstrip("#")
diff --git a/tests/basic/test_editblock.py b/tests/basic/test_editblock.py
index d80952bbe..e93edb7c3 100644
--- a/tests/basic/test_editblock.py
+++ b/tests/basic/test_editblock.py
@@ -108,29 +108,6 @@ Hope you like it!
         edits = list(eb.find_original_update_blocks(edit))
         self.assertEqual(edits, [("foo.txt", "Two\n", "Tooooo\n")])
 
-    def test_find_original_update_blocks_mangled_filename_w_source_tag(self):
-        source = "source"
-
-        edit = """
-Here's the change:
-
-<%s>foo.txt
-<<<<<<< SEARCH
-One
-=======
-Two
->>>>>>> REPLACE
-</%s>
-
-Hope you like it!
-""" % (source, source)
-
-        fence = ("<%s>" % source, "</%s>" % source)
-
-        with self.assertRaises(ValueError) as cm:
-            _edits = list(eb.find_original_update_blocks(edit, fence))
-        self.assertIn("missing filename", str(cm.exception))
-
     def test_find_original_update_blocks_quote_below_filename(self):
         edit = """
 Here's the change:
@@ -181,10 +158,11 @@ Tooooo
 
 
 oops!
+>>>>>>> REPLACE
 """
 
         with self.assertRaises(ValueError) as cm:
-            list(eb.find_original_update_blocks(edit))
+            _blocks = list(eb.find_original_update_blocks(edit))
         self.assertIn("filename", str(cm.exception))
 
     def test_find_original_update_blocks_no_final_newline(self):
@@ -575,7 +553,7 @@ Hope you like it!
         edits = list(eb.find_original_update_blocks(edit, fence=quad_backticks))
         self.assertEqual(edits, [("foo.txt", "", "Tooooo\n")])
 
-    #Test for shell script blocks with sh language identifier (issue #3785)
+    # Test for shell script blocks with sh language identifier (issue #3785)
     def test_find_original_update_blocks_with_sh_language_identifier(self):
         # https://github.com/Aider-AI/aider/issues/3785
         edit = """
@@ -609,13 +587,13 @@ exit 0
         # Check that the content contains the expected shell script elements
         result_content = edits[0][2]
         self.assertIn("#!/bin/bash", result_content)
-        self.assertIn("if [ \"$#\" -ne 1 ];", result_content)
-        self.assertIn("echo \"Usage: $0 <argument>\"", result_content)
+        self.assertIn('if [ "$#" -ne 1 ];', result_content)
+        self.assertIn('echo "Usage: $0 <argument>"', result_content)
         self.assertIn("exit 1", result_content)
-        self.assertIn("echo \"$1\"", result_content)
+        self.assertIn('echo "$1"', result_content)
         self.assertIn("exit 0", result_content)
 
-    #Test for C# code blocks with csharp language identifier
+    # Test for C# code blocks with csharp language identifier
     def test_find_original_update_blocks_with_csharp_language_identifier(self):
         edit = """
 Here's a C# code change:
@@ -631,12 +609,9 @@ Console.WriteLine("Hello, C# World!");
 """
 
         edits = list(eb.find_original_update_blocks(edit))
-        search_text = "Console.WriteLine(\"Hello World!\");\n"
-        replace_text = "Console.WriteLine(\"Hello, C# World!\");\n"
-        self.assertEqual(
-            edits,
-            [("Program.cs", search_text, replace_text)]
-        )
+        search_text = 'Console.WriteLine("Hello World!");\n'
+        replace_text = 'Console.WriteLine("Hello, C# World!");\n'
+        self.assertEqual(edits, [("Program.cs", search_text, replace_text)])
 
 
 if __name__ == "__main__":