diff --git a/src/util/memory.h b/src/util/memory.h
index 87cf2cc40..9fab2fd44 100644
--- a/src/util/memory.h
+++ b/src/util/memory.h
@@ -124,7 +124,7 @@ void *mem_realloc(void *, size_t);
 static inline void *
 mem_align_alloc__(
 #ifdef DEBUG_MEMLEAK
-		  unsigned char *file, int line,
+		  const unsigned char *file, int line,
 #endif
 		  void **ptr, size_t old, size_t new, size_t objsize, size_t mask)
 {
diff --git a/src/util/string.h b/src/util/string.h
index 059a8c191..21432fcd1 100644
--- a/src/util/string.h
+++ b/src/util/string.h
@@ -214,7 +214,7 @@ squeezastring(struct string *string)
 static inline struct string *
 add_bytes_to_string__(
 #ifdef DEBUG_MEMLEAK
-		    unsigned char *file, int line,
+		    const unsigned char *file, int line,
 #endif
 		    struct string *string, const unsigned char *bytes,
 		    int length)