diff --git a/include/mem.h b/include/mem.h
index 4bafece..2979f15 100644
--- a/include/mem.h
+++ b/include/mem.h
@@ -13,15 +13,15 @@
 
 
 extern const Exception out_of_memory; // OOM Exception 
-extern void *mem_alloc (size_t nbytes,const char *file, int line);
-extern void *mem_calloc(size_t count, size_t nbytes,const char *file, int line);
+extern void *mem_alloc (ptrdiff_t nbytes,const char *file, int line);
+extern void *mem_calloc(ptrdiff_t count, ptrdiff_t nbytes,const char *file, int line);
 extern void mem_free(void *ptr, const char *file, int line);
-extern void *mem_realloc(void *ptr, size_t nbytes, const char *file, int line);
+extern void *mem_realloc(void *ptr, ptrdiff_t nbytes, const char *file, int line);
 
 #define ALLOC(nbytes) mem_alloc((nbytes), __FILE__, __LINE__)
 #define CALLOC(count, nbytes) mem_calloc((count), (nbytes), __FILE__, __LINE__)
-#define NEW(p) ((p) = ALLOC((size_t)sizeof *(p)))
-#define NEW0(p) ((p) = CALLOC(1, (size_t)sizeof *(p)))
+#define NEW(p) ((p) = ALLOC((ptrdiff_t)sizeof *(p)))
+#define NEW0(p) ((p) = CALLOC(1, (ptrdiff_t)sizeof *(p)))
 #define FREE(ptr) ((void)(mem_free((ptr), __FILE__, __LINE__), (ptr) = 0))
 #define REALLOC(ptr, nbytes) 	((ptr) = mem_realloc((ptr), (nbytes), __FILE__, __LINE__))
 
diff --git a/src/mem.c b/src/mem.c
index 270587e..eadafeb 100644
--- a/src/mem.c
+++ b/src/mem.c
@@ -4,7 +4,7 @@
 
 const Exception out_of_memory = { "Out Of Memory" }; // OOM Exception.
 
-void *mem_alloc(size_t nbytes, const char *file, int  line){
+void *mem_alloc(ptrdiff_t nbytes, const char *file, int  line){
     void *ptr; // Memory to allocate.
     ASSERTED(nbytes > 0); 
     ptr = malloc(nbytes); // Attempt allocation.
@@ -17,7 +17,7 @@ void *mem_alloc(size_t nbytes, const char *file, int  line){
     // Success, return allocated memory. 
     return ptr;
 }
-void *mem_calloc(size_t count, size_t nbytes,const char *file, int line) {
+void *mem_calloc(ptrdiff_t count, ptrdiff_t nbytes,const char *file, int line) {
     void *ptr; // Memory to allocate.
     ASSERTED(count > 0);
     ASSERTED(nbytes > 0);
@@ -39,7 +39,7 @@ void mem_free(void *ptr, const char *file, int line) {
         ptr = NULL;
     }
 }
-void *mem_realloc(void *ptr, size_t nbytes, const char *file, int line) {
+void *mem_realloc(void *ptr, ptrdiff_t nbytes, const char *file, int line) {
     ASSERTED(ptr);
     ASSERTED(nbytes > 0);
     ptr = realloc(ptr, nbytes); // Attempt reallocation.