diff --git a/dtool/src/dtoolbase/memoryHook.cxx b/dtool/src/dtoolbase/memoryHook.cxx
index f160f956f4..cd6370d9d3 100644
--- a/dtool/src/dtoolbase/memoryHook.cxx
+++ b/dtool/src/dtoolbase/memoryHook.cxx
@@ -275,7 +275,7 @@ heap_free_single(void *ptr) {
   void *alloc = ptr_to_alloc(ptr, size);
 
 #ifdef DO_MEMORY_USAGE
-  assert((int)size <= _total_heap_single_size.load(std::memory_order_relaxed));
+  assert(size <= _total_heap_single_size.load(std::memory_order_relaxed));
   _total_heap_single_size.fetch_sub(size, std::memory_order_relaxed);
 #endif  // DO_MEMORY_USAGE
 
@@ -423,7 +423,7 @@ heap_free_array(void *ptr) {
   void *alloc = ptr_to_alloc(ptr, size);
 
 #ifdef DO_MEMORY_USAGE
-  assert((int)size <= _total_heap_array_size);
+  assert(size <= _total_heap_array_size);
   _total_heap_array_size.fetch_sub(size, std::memory_order_relaxed);
 #endif  // DO_MEMORY_USAGE
 
@@ -544,7 +544,7 @@ mmap_free(void *ptr, size_t size) {
   assert((size % _page_size) == 0);
 
 #ifdef DO_MEMORY_USAGE
-  assert((int)size <= _total_mmap_size.load(std::memory_order_relaxed));
+  assert(size <= _total_mmap_size.load(std::memory_order_relaxed));
   _total_mmap_size.fetch_sub(size, std::memory_order_relaxed);
 #endif