diff --git a/CHANGELOG.md b/CHANGELOG.md
index e7f36ac..0b1656b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 
 ## Next Release
 
+### Features
+
+#### CPP Rules
+
+- make it possible to check header guards also for `.tpp` and `.impl.hpp` files
+
 <!-- insertion marker -->
 ## [0.1.0](https://github.com/repo/owner/releases/tag/0.1.0) - 2026-01-18
 
diff --git a/src/devops/cpp/style_rules.py b/src/devops/cpp/style_rules.py
index 75fd7f6..ffc944e 100644
--- a/src/devops/cpp/style_rules.py
+++ b/src/devops/cpp/style_rules.py
@@ -145,10 +145,21 @@ def check_header_guards(file_rule_input: FileRuleInput) -> ResultType:
         expected_macro = str(path).upper()
         expected_macro = expected_macro.removeprefix("INCLUDE/")
         expected_macro = expected_macro.removeprefix("TEST/")
+        expected_macro = expected_macro.removeprefix("SRC/")
         expected_macro = expected_macro.replace("/", "__")
-        expected_macro = expected_macro.removesuffix(".HPP")
-        expected_macro = expected_macro.removesuffix(".H")
-        expected_macro = "__" + expected_macro + "_HPP__"
+
+        if expected_macro.endswith(".IMPL.HPP"):
+            expected_macro = expected_macro.removesuffix(".IMPL.HPP")
+            expected_macro = "__" + expected_macro + "_IMPL_HPP__"
+        elif expected_macro.endswith(".HPP"):
+            expected_macro = expected_macro.removesuffix(".HPP")
+            expected_macro = "__" + expected_macro + "_HPP__"
+        elif expected_macro.endswith(".TPP"):
+            expected_macro = expected_macro.removesuffix(".TPP")
+            expected_macro = "__" + expected_macro + "_TPP__"
+        elif expected_macro.endswith(".H"):
+            expected_macro = expected_macro.removesuffix(".H")
+            expected_macro = "__" + expected_macro + "_H__"
 
         if guard_macro != expected_macro:
             msg = (
diff --git a/src/devops/files/files.py b/src/devops/files/files.py
index cb53400..6d54aad 100644
--- a/src/devops/files/files.py
+++ b/src/devops/files/files.py
@@ -85,7 +85,7 @@ def determine_file_type(filename: str | Path) -> FileType:
     """
     filename = str(filename)
 
-    if filename.endswith((".h", ".hpp")):
+    if filename.endswith((".h", ".hpp", ".tpp", ".impl.hpp")):
         return FileType.CPPHeader
     if filename.endswith((".cpp", ".cxx", ".cc", ".c")):
         return FileType.CPPSource
diff --git a/tests/cpp/test_style_rules.py b/tests/cpp/test_style_rules.py
index 8e4f8cd..8990eef 100644
--- a/tests/cpp/test_style_rules.py
+++ b/tests/cpp/test_style_rules.py
@@ -610,8 +610,8 @@ class MockClass {};
 
     def test_check_header_guards_with_h_extension(self) -> None:
         """Test header guards with .h extension."""
-        file_content = """#ifndef __MYHEADER_HPP__
-#define __MYHEADER_HPP__
+        file_content = """#ifndef __MYHEADER_H__
+#define __MYHEADER_H__
 
 void myFunction();