diff --git a/src/gpgmm/utils/Assert.h b/src/gpgmm/utils/Assert.h
index 466720cc0..5c421c8e8 100644
--- a/src/gpgmm/utils/Assert.h
+++ b/src/gpgmm/utils/Assert.h
@@ -49,9 +49,17 @@
 #else
 #    if defined(GPGMM_COMPILER_MSVC)
 #        define GPGMM_ASSERT_CALLSITE_HELPER(file, func, line, condition) __assume(condition)
-#    elif defined(GPGMM_COMPILER_CLANG) && defined(__builtin_assume)
+#    elif defined(GPGMM_COMPILER_CLANG) && GPGMM_HAS_BUILTIN(__builtin_unreachable)
+// Avoid using __builtin_assume since it results into clang assuming _every_ function call has a
+// side effect. Alternatively, suppress these warnings with -Wno-assume or wrap _builtin_assume in
+// pragmas. Since the generated code below is equivelent, replacing with __builtin_unreachable is
+// used.
 #        define GPGMM_ASSERT_CALLSITE_HELPER(file, func, line, condition) \
-            __builtin_assume(condition)
+            do {                                                          \
+                if (!(condition)) {                                       \
+                    GPGMM_BUILTIN_UNREACHABLE();                          \
+                }                                                         \
+            } while (GPGMM_ASSERT_LOOP_CONDITION)
 #    else
 #        define GPGMM_ASSERT_CALLSITE_HELPER(file, func, line, condition) \
             do {                                                          \
diff --git a/src/gpgmm/utils/Compiler.h b/src/gpgmm/utils/Compiler.h
index 5dc2ff00e..65468ac49 100644
--- a/src/gpgmm/utils/Compiler.h
+++ b/src/gpgmm/utils/Compiler.h
@@ -80,6 +80,11 @@ extern void __cdecl __debugbreak(void);
 #    error "Unsupported compiler"
 #endif
 
+// Non-compiler specific language extensions
+#if defined(__has_builtin)
+#    define GPGMM_HAS_BUILTIN __has_builtin
+#endif
+
 // It seems that (void) EXPR works on all compilers to silence the unused variable warning.
 #define GPGMM_UNUSED(EXPR) (void)EXPR
 // Likewise using static asserting on sizeof(&FUNC) seems to make it tagged as used
@@ -98,6 +103,9 @@ extern void __cdecl __debugbreak(void);
 #if !defined(GPGMM_FORCE_INLINE)
 #    define GPGMM_FORCE_INLINE inline
 #endif
+#if !defined(GPGMM_HAS_BUILTIN)
+#    define GPGMM_HAS_BUILTIN(X) 0
+#endif
 
 #if defined(__clang__)
 #    define GPGMM_FALLTHROUGH [[clang::fallthrough]]