diff --git a/src/system/libroot/posix/malloc/arch-specific.cpp b/src/system/libroot/posix/malloc/arch-specific.cpp
index 8cb1f6723b..6151fa6407 100644
--- a/src/system/libroot/posix/malloc/arch-specific.cpp
+++ b/src/system/libroot/posix/malloc/arch-specific.cpp
@@ -179,7 +179,7 @@ hoardSbrk(long size)
 
 		if (chunk->size > (size_t)size + sizeof(free_chunk)) {
 			// divide this chunk into smaller bits
-			uint32 newSize = chunk->size - size;
+			size_t newSize = chunk->size - size;
 			free_chunk *next = chunk->next;
 
 			chunk = (free_chunk *)((addr_t)chunk + size);
diff --git a/src/system/libroot/posix/malloc/superblock.cpp b/src/system/libroot/posix/malloc/superblock.cpp
index 05b6bc4380..5114ad8264 100644
--- a/src/system/libroot/posix/malloc/superblock.cpp
+++ b/src/system/libroot/posix/malloc/superblock.cpp
@@ -67,7 +67,7 @@ superblock::superblock(int numBlocks,	// The number of blocks in the sb.
 	// and insert the block pointers into the linked list.
 	for (int i = 0; i < _numBlocks; i++) {
 		// Make sure the block is on a double-word boundary.
-		assert(((unsigned int)b & hoardHeap::ALIGNMENT_MASK) == 0);
+		assert(((unsigned long)b & hoardHeap::ALIGNMENT_MASK) == 0);
 		new(b) block(this);
 		assert(b->getSuperblock() == this);
 		b->setNext(_freeList);