diff --git a/src/boot/pmm.c b/src/boot/pmm.c
index 6eefed8..e6d297f 100644
--- a/src/boot/pmm.c
+++ b/src/boot/pmm.c
@@ -13,15 +13,15 @@
 static u64 pmm_bitmap[BITMAP_SIZE];
 
 static inline void bitmap_set(size_t bit) {
-    pmm_bitmap[bit / 64] |=  (U64_C(1) << (bit % 64));
+    pmm_bitmap[bit / 64] |=  (1ULL << (bit % 64));
 }
 
 static inline void bitmap_clear(size_t bit) {
-    pmm_bitmap[bit / 64] &= ~(U64_C(1) << (bit % 64));
+    pmm_bitmap[bit / 64] &= ~(1ULL << (bit % 64));
 }
 
 static inline int bitmap_test(size_t bit) {
-    return pmm_bitmap[bit / 64] & (U64_C(1) << (bit % 64));
+    return pmm_bitmap[bit / 64] & (1ULL << (bit % 64));
 }
 
 static inline size_t to_page(uptr addr) {
diff --git a/src/shared/def.h b/src/shared/def.h
index 9d6bd74..4a0ff5e 100644
--- a/src/shared/def.h
+++ b/src/shared/def.h
@@ -53,19 +53,7 @@ typedef signed long long i64;
 #define U64_MIN 0x0
 #define U64_MAX 0xffffffffffffffffULL
 
-#define I8_C(x) x
-#define U8_C(x) x##U
-
-#define I16_C(x) x
-#define U16_C(x) x##U
-
-#define I32_C(x) x
-#define U32_C(x) x##U
-
-#define I64_C(x) x##LL
-#define U64_C(x) x##ULL
-
-#define KiB(count) (U64_C(count) * U64_C(1024))
-#define MiB(count) (U64_C(count) * KiB(1024))
-#define GiB(count) (U64_C(count) * MiB(1024))
-#define TiB(count) (U64_C(count) * GiB(1024))
\ No newline at end of file
+#define KiB(count) (count##ULL * 1024##ULL)
+#define MiB(count) (count##ULL * KiB(1024))
+#define GiB(count) (count##ULL * MiB(1024))
+#define TiB(count) (count##ULL * GiB(1024))
\ No newline at end of file