diff --git a/README.md b/README.md
index d088f8375..b6928921d 100644
--- a/README.md
+++ b/README.md
@@ -209,3 +209,7 @@ The coverage is generated via ``gcov`` and evaluated by
 | AppleClang-18.1.6 |     -     |    x   |    x   |    x   |
 
 As new compilers become available, they will be added to the workflow, but older compilers will probably never be supported.
+
+## Known Issues
+
+* Clang-18.1 introduced a regression regarding the ``std::invocable`` concept and a default parameter of type ``std::source_location``. On this version, all invocable checks will fail. Clang-17 and Clang-19 do not suffer from this issue.
diff --git a/test/unit-tests/Mock.cpp b/test/unit-tests/Mock.cpp
index a37050326..0ba171ce8 100644
--- a/test/unit-tests/Mock.cpp
+++ b/test/unit-tests/Mock.cpp
@@ -19,6 +19,20 @@
 
 using namespace mimicpp;
 
+// This disables the std::invocable checks for Mocks, due to an issue on clang 18.1
+// see: https://github.com/llvm/llvm-project/issues/106428
+#if defined(__clang_major__) \
+	&& __clang_major__ == 18 \
+	&& __clang_minor__ == 1
+
+	#define CLANG_18_STD_INVOCABLE_REGRESSION
+
+	// Should fail, when the regression has been resolved.
+	// If so, enable the tests and remove the issue from the ``Known Issues`` section in the readme.
+	static_assert(!std::invocable<Mock<void()>>);
+
+#endif
+
 TEMPLATE_TEST_CASE(
 	"Mock is a non-copyable, but movable and default-constructible type.",
 	"[mock]",
@@ -66,23 +80,52 @@ TEMPLATE_TEST_CASE_SIG(
 	using NothrowMockT = Mock<signature_add_noexcept_t<Sig>>;
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT, Args...>);
-	STATIC_REQUIRE(std::invocable<NothrowMockT, Args...>);
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT&, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT&, Args...>);
-	STATIC_REQUIRE(std::invocable<NothrowMockT&, Args...>);
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT&&, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT&&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT&&, Args...>);
+
+	// negative checks
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const MockT, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const MockT&, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const MockT&&, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const NothrowMockT&&, Args...>);
+
+#ifndef CLANG_18_STD_INVOCABLE_REGRESSION
+
+	STATIC_REQUIRE(std::invocable<MockT, Args...>);
+	STATIC_REQUIRE(std::invocable<NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(std::invocable<MockT&, Args...>);
+	STATIC_REQUIRE(std::invocable<NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(std::invocable<MockT&&, Args...>);
 	STATIC_REQUIRE(std::invocable<NothrowMockT&&, Args...>);
+
+	// negative checks
+
+	STATIC_REQUIRE(!std::invocable<const MockT, Args...>);
+	STATIC_REQUIRE(!std::invocable<const NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(!std::invocable<const MockT&, Args...>);
+	STATIC_REQUIRE(!std::invocable<const NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(!std::invocable<const MockT&&, Args...>);
+	STATIC_REQUIRE(!std::invocable<const NothrowMockT&&, Args...>);
+
+#endif
 }
 
 TEMPLATE_TEST_CASE_SIG(
-	"Mutable Mock specialization is an invocable type.",
+	"Const Mock specialization is an invocable type.",
 	"[mock]",
 	((bool dummy, typename Sig, typename... Args), dummy, Sig, Args...),
 	(true, void() const),
@@ -98,29 +141,44 @@ TEMPLATE_TEST_CASE_SIG(
 	using NothrowMockT = Mock<signature_add_noexcept_t<Sig>>;
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT, Args...>);
-	STATIC_REQUIRE(std::invocable<NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const MockT, Args...>);
+	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const NothrowMockT, Args...>);
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT&, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT&, Args...>);
-	STATIC_REQUIRE(std::invocable<NothrowMockT&, Args...>);
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const MockT&, Args...>);
-	STATIC_REQUIRE(std::invocable<const MockT&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const NothrowMockT&, Args...>);
-	STATIC_REQUIRE(std::invocable<const NothrowMockT&, Args...>);
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT&&, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT&&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT&&, Args...>);
-	STATIC_REQUIRE(std::invocable<NothrowMockT&&, Args...>);
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const MockT&&, Args...>);
-	STATIC_REQUIRE(std::invocable<const MockT&&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const NothrowMockT&&, Args...>);
+
+#ifndef CLANG_18_STD_INVOCABLE_REGRESSION
+
+	STATIC_REQUIRE(std::invocable<MockT, Args...>);
+	STATIC_REQUIRE(std::invocable<NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(std::invocable<const MockT, Args...>);
+	STATIC_REQUIRE(std::invocable<const NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(std::invocable<MockT&, Args...>);
+	STATIC_REQUIRE(std::invocable<NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(std::invocable<const MockT&, Args...>);
+	STATIC_REQUIRE(std::invocable<const NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(std::invocable<MockT&&, Args...>);
+	STATIC_REQUIRE(std::invocable<NothrowMockT&&, Args...>);
+
+	STATIC_REQUIRE(std::invocable<const MockT&&, Args...>);
 	STATIC_REQUIRE(std::invocable<const NothrowMockT&&, Args...>);
+
+#endif
 }
 
 TEMPLATE_TEST_CASE_SIG(
@@ -140,9 +198,48 @@ TEMPLATE_TEST_CASE_SIG(
 	using NothrowMockT = Mock<signature_add_noexcept_t<Sig>>;
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT&, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT&, Args...>);
+
+	// negative checks
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, MockT, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const MockT, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const MockT&, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, MockT&&, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, NothrowMockT&&, Args...>);
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const MockT&&, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const NothrowMockT&&, Args...>);
+
+#ifndef CLANG_18_STD_INVOCABLE_REGRESSION
+
+	STATIC_REQUIRE(std::invocable<MockT&, Args...>);
 	STATIC_REQUIRE(std::invocable<NothrowMockT&, Args...>);
+
+	// negative checks
+
+	STATIC_REQUIRE(!std::invocable<MockT, Args...>);
+	STATIC_REQUIRE(!std::invocable<NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(!std::invocable<const MockT, Args...>);
+	STATIC_REQUIRE(!std::invocable<const NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(!std::invocable<const MockT&, Args...>);
+	STATIC_REQUIRE(!std::invocable<const NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(!std::invocable<MockT&&, Args...>);
+	STATIC_REQUIRE(!std::invocable<NothrowMockT&&, Args...>);
+
+	STATIC_REQUIRE(!std::invocable<const MockT&&, Args...>);
+	STATIC_REQUIRE(!std::invocable<const NothrowMockT&&, Args...>);
+
+#endif
 }
 
 TEMPLATE_TEST_CASE_SIG(
@@ -162,29 +259,44 @@ TEMPLATE_TEST_CASE_SIG(
 	using NothrowMockT = Mock<signature_add_noexcept_t<Sig>>;
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT, Args...>);
-	STATIC_REQUIRE(std::invocable<NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const MockT, Args...>);
+	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const NothrowMockT, Args...>);
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT&, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT&, Args...>);
-	STATIC_REQUIRE(std::invocable<NothrowMockT&, Args...>);
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const MockT&, Args...>);
-	STATIC_REQUIRE(std::invocable<const MockT&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const NothrowMockT&, Args...>);
-	STATIC_REQUIRE(std::invocable<const NothrowMockT&, Args...>);
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT&&, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT&&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT&&, Args...>);
-	STATIC_REQUIRE(std::invocable<NothrowMockT&&, Args...>);
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const MockT&&, Args...>);
-	STATIC_REQUIRE(std::invocable<const MockT&&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const NothrowMockT&&, Args...>);
+
+#ifndef CLANG_18_STD_INVOCABLE_REGRESSION
+
+	STATIC_REQUIRE(std::invocable<MockT, Args...>);
+	STATIC_REQUIRE(std::invocable<NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(std::invocable<const MockT, Args...>);
+	STATIC_REQUIRE(std::invocable<const NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(std::invocable<MockT&, Args...>);
+	STATIC_REQUIRE(std::invocable<NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(std::invocable<const MockT&, Args...>);
+	STATIC_REQUIRE(std::invocable<const NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(std::invocable<MockT&&, Args...>);
+	STATIC_REQUIRE(std::invocable<NothrowMockT&&, Args...>);
+
+	STATIC_REQUIRE(std::invocable<const MockT&&, Args...>);
 	STATIC_REQUIRE(std::invocable<const NothrowMockT&&, Args...>);
+
+#endif
 }
 
 TEMPLATE_TEST_CASE_SIG(
@@ -204,14 +316,48 @@ TEMPLATE_TEST_CASE_SIG(
 	using NothrowMockT = Mock<signature_add_noexcept_t<Sig>>;
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT, Args...>);
-	STATIC_REQUIRE(std::invocable<NothrowMockT, Args...>);
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT&&, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT&&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT&&, Args...>);
+
+	// negative checks
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const MockT, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, MockT&, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const MockT&, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const MockT&&, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const NothrowMockT&&, Args...>);
+
+#ifndef CLANG_18_STD_INVOCABLE_REGRESSION
+
+	STATIC_REQUIRE(std::invocable<MockT, Args...>);
+	STATIC_REQUIRE(std::invocable<NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(std::invocable<MockT&&, Args...>);
 	STATIC_REQUIRE(std::invocable<NothrowMockT&&, Args...>);
+
+	// negative checks
+
+	STATIC_REQUIRE(!std::invocable<const MockT, Args...>);
+	STATIC_REQUIRE(!std::invocable<const NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(!std::invocable<MockT&, Args...>);
+	STATIC_REQUIRE(!std::invocable<NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(!std::invocable<const MockT&, Args...>);
+	STATIC_REQUIRE(!std::invocable<const NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(!std::invocable<const MockT&&, Args...>);
+	STATIC_REQUIRE(!std::invocable<const NothrowMockT&&, Args...>);
+
+#endif
 }
 
 TEMPLATE_TEST_CASE_SIG(
@@ -231,19 +377,48 @@ TEMPLATE_TEST_CASE_SIG(
 	using NothrowMockT = Mock<signature_add_noexcept_t<Sig>>;
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT, Args...>);
-	STATIC_REQUIRE(std::invocable<NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const MockT, Args...>);
+	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const NothrowMockT, Args...>);
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, MockT&&, Args...>);
-	STATIC_REQUIRE(std::invocable<MockT&&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, NothrowMockT&&, Args...>);
-	STATIC_REQUIRE(std::invocable<NothrowMockT&&, Args...>);
 
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const MockT&&, Args...>);
-	STATIC_REQUIRE(std::invocable<const MockT&&, Args...>);
 	STATIC_REQUIRE(std::is_invocable_r_v<ReturnT, const NothrowMockT&&, Args...>);
+
+	// negative checks
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, MockT&, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const MockT&, Args...>);
+	STATIC_REQUIRE(!std::is_invocable_r_v<ReturnT, const NothrowMockT&, Args...>);
+
+#ifndef CLANG_18_STD_INVOCABLE_REGRESSION
+
+	STATIC_REQUIRE(std::invocable<MockT, Args...>);
+	STATIC_REQUIRE(std::invocable<NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(std::invocable<const MockT, Args...>);
+	STATIC_REQUIRE(std::invocable<const NothrowMockT, Args...>);
+
+	STATIC_REQUIRE(std::invocable<MockT&&, Args...>);
+	STATIC_REQUIRE(std::invocable<NothrowMockT&&, Args...>);
+
+	STATIC_REQUIRE(std::invocable<const MockT&&, Args...>);
 	STATIC_REQUIRE(std::invocable<const NothrowMockT&&, Args...>);
+
+	// negative checks
+
+	STATIC_REQUIRE(!std::invocable<MockT&, Args...>);
+	STATIC_REQUIRE(!std::invocable<NothrowMockT&, Args...>);
+
+	STATIC_REQUIRE(!std::invocable<const MockT&, Args...>);
+	STATIC_REQUIRE(!std::invocable<const NothrowMockT&, Args...>);
+
+#endif
 }
 
 TEST_CASE(