diff --git a/arch/sandbox/include/asm/io.h b/arch/sandbox/include/asm/io.h
index 9ac6a5f00d..7956041171 100644
--- a/arch/sandbox/include/asm/io.h
+++ b/arch/sandbox/include/asm/io.h
@@ -38,6 +38,6 @@ static inline void unmap_sysmem(const void *vaddr)
 }
 
 /* Map from a pointer to our RAM buffer */
-phys_addr_t map_to_sysmem(void *ptr);
+phys_addr_t map_to_sysmem(const void *ptr);
 
 #endif
diff --git a/include/common.h b/include/common.h
index 409515f498..8ca67f64fa 100644
--- a/include/common.h
+++ b/include/common.h
@@ -923,7 +923,7 @@ static inline void unmap_sysmem(const void *vaddr)
 {
 }
 
-static inline phys_addr_t map_to_sysmem(void *ptr)
+static inline phys_addr_t map_to_sysmem(const void *ptr)
 {
 	return (phys_addr_t)(uintptr_t)ptr;
 }