diff --git a/src/hos/memory.d b/src/hos/memory.d
index f66f631..ff1da4a 100644
--- a/src/hos/memory.d
+++ b/src/hos/memory.d
@@ -28,28 +28,28 @@ void memset64(void * dest, ulong v, size_t n)
           v, n, dest);
 }
 
-void memcpy(void * dest, void * src, size_t n)
+void memcpy(void * dest, const(void) * src, size_t n)
 {
     __asm("rep movsb",
           "{rcx},{rsi},{rdi},~{rcx},~{rsi},~{rdi},~{memory}",
           n, src, dest);
 }
 
-void memcpy16(void * dest, void * src, size_t n)
+void memcpy16(void * dest, const(void) * src, size_t n)
 {
     __asm("rep movsw",
           "{rcx},{rsi},{rdi},~{rcx},~{rsi},~{rdi},~{memory}",
           n, src, dest);
 }
 
-void memcpy32(void * dest, void * src, size_t n)
+void memcpy32(void * dest, const(void) * src, size_t n)
 {
     __asm("rep movsl",
           "{rcx},{rsi},{rdi},~{rcx},~{rsi},~{rdi},~{memory}",
           n, src, dest);
 }
 
-void memcpy64(void * dest, void * src, size_t n)
+void memcpy64(void * dest, const(void) * src, size_t n)
 {
     __asm("rep movsq",
           "{rcx},{rsi},{rdi},~{rcx},~{rsi},~{rdi},~{memory}",