diff --git a/AK/Assertions.cpp b/AK/Assertions.cpp
index 9334a49ad57..e0bceefe9b5 100644
--- a/AK/Assertions.cpp
+++ b/AK/Assertions.cpp
@@ -96,6 +96,27 @@ void ak_verification_failed(char const* message)
     else
         ERRORLN("VERIFICATION FAILED: {}", message);
 
+#if defined(AK_HAS_BACKTRACE_HEADER)
+    dump_backtrace();
+#endif
+    __builtin_trap();
+}
+
+void ak_assertion_failed(char const* message)
+{
+#if defined(AK_OS_SERENITY) || defined(AK_OS_ANDROID)
+    bool colorize_output = true;
+#elif defined(AK_OS_WINDOWS)
+    bool colorize_output = false;
+#else
+    bool colorize_output = isatty(STDERR_FILENO) == 1;
+#endif
+
+    if (colorize_output)
+        ERRORLN("\033[31;1mASSERTION FAILED\033[0m: {}", message);
+    else
+        ERRORLN("ASSERTION FAILED: {}", message);
+
 #if defined(AK_HAS_BACKTRACE_HEADER)
     dump_backtrace();
 #endif
diff --git a/AK/Assertions.h b/AK/Assertions.h
index ba28c914b5e..7355fefeda9 100644
--- a/AK/Assertions.h
+++ b/AK/Assertions.h
@@ -20,3 +20,15 @@ static constexpr bool TODO = false;
 #define TODO_RISCV64() VERIFY(TODO) /* NOLINT(cert-dcl03-c,misc-static-assert) No, this can't be static_assert, it's a runtime check */
 #define TODO_PPC64() VERIFY(TODO)   /* NOLINT(cert-dcl03-c,misc-static-assert) No, this can't be static_assert, it's a runtime check */
 #define TODO_PPC() VERIFY(TODO)     /* NOLINT(cert-dcl03-c,misc-static-assert) No, this can't be static_assert, it's a runtime check */
+
+#ifdef NDEBUG
+extern "C" __attribute__((noreturn)) void ak_assertion_failed(char const*);
+#    define ASSERT(expr)                                                               \
+        (__builtin_expect(!(expr), 0)                                                  \
+                ? ak_assertion_failed(#expr " at " __FILE__ ":" __stringify(__LINE__)) \
+                : (void)0)
+#    define ASSERT_NOT_REACHED ASSERT(false) /* NOLINT(cert-dcl03-c,misc-static-assert) No, this can't be static_assert, it's a runtime check */
+#else
+#    define ASSERT(expr)
+#    define ASSERT_NOT_REACHED() __builtin_unreachable()
+#endif