diff --git a/src/vuln_analysis/utils/function_name_extractor.py b/src/vuln_analysis/utils/function_name_extractor.py
index 7f955f330..d58b2a789 100644
--- a/src/vuln_analysis/utils/function_name_extractor.py
+++ b/src/vuln_analysis/utils/function_name_extractor.py
@@ -25,9 +25,12 @@
 
 def traverse_all_parameters(function_ending_index_end, function_prefix_index_end, function_string):
     current_idx = function_prefix_index_end
-    function_builder = function_string[:function_prefix_index_end]
+    # Escape the function name prefix so regex metacharacters (., [], +, etc.)
+    # in identifiers like "protojson.Unmarshal" or "[]byte" are treated as literals.
+    prefix_name = function_string[:function_prefix_index_end - 1]
+    function_builder = re.escape(prefix_name) + r"\("
     if current_idx == function_ending_index_end:
-        function_builder += ")"
+        function_builder += r"\)"
     while current_idx < function_ending_index_end:
         end_of_arg_ind = function_string[current_idx:].find(",")
         if end_of_arg_ind > -1:
@@ -37,7 +40,7 @@ def traverse_all_parameters(function_ending_index_end, function_prefix_index_end
         else:
             # last argument
             value = handle_argument(function_string[current_idx:function_ending_index_end].strip())
-            function_builder += f"\\s?{value}\\s?)"
+            function_builder += f"\\s?{value}\\s?\\)"
             current_idx = function_ending_index_end
 
     return function_builder
@@ -69,7 +72,7 @@ def handle_argument(param: str) -> str:
     :return: returns the right matcher.
     """
     if (param.startswith("'") and param.endswith("'")) or (param.startswith('"') and param.endswith('"')):
-        return param
+        return re.escape(param)
     elif param.__contains__("(") and param.__contains__(")"):
         function_prefix_index_end = param.find("(") + 1
         function_ending_index_end = param.rfind(")")