diff --git a/AK/StdLibExtras.h b/AK/StdLibExtras.h
index e71d7497ef..9a8928d641 100644
--- a/AK/StdLibExtras.h
+++ b/AK/StdLibExtras.h
@@ -146,14 +146,16 @@ constexpr bool is_constant_evaluated()
     }
 
 __DEFINE_GENERIC_ABS(int, 0, abs);
-__DEFINE_GENERIC_ABS(long, 0l, labs);
-__DEFINE_GENERIC_ABS(long long, 0ll, llabs);
+__DEFINE_GENERIC_ABS(long, 0L, labs);
+__DEFINE_GENERIC_ABS(long long, 0LL, llabs);
 #ifndef KERNEL
-__DEFINE_GENERIC_ABS(float, 0.0f, fabsf);
+__DEFINE_GENERIC_ABS(float, 0.0F, fabsf);
 __DEFINE_GENERIC_ABS(double, 0.0, fabs);
-__DEFINE_GENERIC_ABS(long double, 0.0l, fabsl);
+__DEFINE_GENERIC_ABS(long double, 0.0L, fabsl);
 #endif
 
+#undef __DEFINE_GENERIC_ABS
+
 }
 
 using AK::array_size;