diff --git a/components/libc/compilers/armlibc/mem_std.c b/components/libc/compilers/armlibc/mem_std.c
index 7fa0033f9d5d880d89ee42bbbf221a9937baec40..138ebe977345a863c226f950e0c007eb59f18617 100644
--- a/components/libc/compilers/armlibc/mem_std.c
+++ b/components/libc/compilers/armlibc/mem_std.c
@@ -19,19 +19,19 @@
 /* avoid the heap and heap-using library functions supplied by arm */
 #pragma import(__use_no_heap)
 
-void *malloc(int n)
+void *malloc(size_t n)
 {
     return rt_malloc(n);
 }
 RTM_EXPORT(malloc);
 
-void *realloc(void *rmem, rt_size_t newsize)
+void *realloc(void *rmem, size_t newsize)
 {
     return rt_realloc(rmem, newsize);
 }
 RTM_EXPORT(realloc);
 
-void *calloc(rt_size_t nelem, rt_size_t elsize)
+void *calloc(size_t nelem, size_t elsize)
 {
     return rt_calloc(nelem, elsize);
 }