diff --git a/common/math.h b/common/math.h
index 85e7d212384..2c2a1554b0d 100644
--- a/common/math.h
+++ b/common/math.h
@@ -66,7 +66,7 @@ struct Complex {
 	float re, im;
 };
 
-#if GCC_ATLEAST(3, 4)
+#if defined(__GNUC__)
 inline int intLog2(uint32 v) {
 	// This is a slightly optimized implementation of log2 for natural numbers
 	// targeting gcc. It also saves some binary size over our fallback
@@ -94,6 +94,7 @@ static const char LogTable256[256] = {
 	-1, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
 	LT(4), LT(5), LT(5), LT(6), LT(6), LT(6), LT(6),
 	LT(7), LT(7), LT(7), LT(7), LT(7), LT(7), LT(7), LT(7)
+#undef LT
 };
 
 inline int intLog2(uint32 v) {