diff --git a/Userland/Libraries/LibC/malloc.cpp b/Userland/Libraries/LibC/malloc.cpp
index a88d1e4cb4..06050b3afd 100644
--- a/Userland/Libraries/LibC/malloc.cpp
+++ b/Userland/Libraries/LibC/malloc.cpp
@@ -24,8 +24,6 @@
 
 #define RECYCLE_BIG_ALLOCATIONS
 
-#define PAGE_ROUND_UP(x) ((((size_t)(x)) + PAGE_SIZE - 1) & (~(PAGE_SIZE - 1)))
-
 static Threading::Lock& malloc_lock()
 {
     static u32 lock_storage[sizeof(Threading::Lock) / sizeof(u32)];
diff --git a/Userland/Libraries/LibC/mallocdefs.h b/Userland/Libraries/LibC/mallocdefs.h
index 991c4b003b..26a40855df 100644
--- a/Userland/Libraries/LibC/mallocdefs.h
+++ b/Userland/Libraries/LibC/mallocdefs.h
@@ -14,6 +14,8 @@
 #define MALLOC_SCRUB_BYTE 0xdc
 #define FREE_SCRUB_BYTE 0xed
 
+#define PAGE_ROUND_UP(x) ((((size_t)(x)) + PAGE_SIZE - 1) & (~(PAGE_SIZE - 1)))
+
 static constexpr unsigned short size_classes[] = { 8, 16, 32, 64, 128, 256, 504, 1016, 2032, 4088, 8184, 16376, 32752, 0 };
 static constexpr size_t num_size_classes = (sizeof(size_classes) / sizeof(unsigned short)) - 1;