diff --git a/userspace/libraries/LibC/malloc.cpp b/userspace/libraries/LibC/malloc.cpp
index 2c44cce5..42eff97e 100644
--- a/userspace/libraries/LibC/malloc.cpp
+++ b/userspace/libraries/LibC/malloc.cpp
@@ -96,8 +96,6 @@ struct BitmapAllocator
 		// NOTE: We could optimize other bitmap functions than this
 		//       but this one is the bottle neck so it doesn't matter
 
-		static_assert(sizeof(unsigned long long) == sizeof(uint64_t));
-
 		if (index >= total_chunks)
 			return index;
 
@@ -105,7 +103,7 @@ struct BitmapAllocator
 		{
 			const uint64_t qword = *reinterpret_cast<const uint64_t*>(base + (index - rem) / 8) >> rem;
 			if (qword != UINT64_MAX >> rem)
-				return index + __builtin_ctzll(~qword);
+				return index + BAN::Math::ctz(~qword);
 			index += 64 - rem;
 		}
 
@@ -113,7 +111,7 @@ struct BitmapAllocator
 		{
 			const uint64_t qword = *reinterpret_cast<const uint64_t*>(base + index / 8);
 			if (qword != UINT64_MAX)
-				return index + __builtin_ctzll(~qword);
+				return index + BAN::Math::ctz(~qword);
 			index += 64;
 		}
 
diff --git a/userspace/libraries/LibQR/QRCode.cpp b/userspace/libraries/LibQR/QRCode.cpp
index 15df284b..2bb7fbb7 100644
--- a/userspace/libraries/LibQR/QRCode.cpp
+++ b/userspace/libraries/LibQR/QRCode.cpp
@@ -771,9 +771,9 @@ namespace LibQR
 		const auto mod2_remainder =
 			[](uint32_t data, uint32_t generator, uint32_t degree)
 			{
-				constexpr auto bits = [](uint32_t val) -> uint32_t { return 31 - __builtin_clz(val | 1); };
-				while (bits(data) >= degree)
-					data ^= generator << (bits(data) - degree);
+				uint32_t bits;
+				while ((bits = BAN::Math::ilog2(data | 1)) >= degree)
+					data ^= generator << (bits - degree);
 				return data;
 			};