diff --git a/src/protocol/header.c b/src/protocol/header.c
index 2c99f9968..c90269bda 100644
--- a/src/protocol/header.c
+++ b/src/protocol/header.c
@@ -232,7 +232,7 @@ parse_header(char *head, const char *item, char **ptr)
  * and cannot fail with HEADER_PARAM_OUT_OF_MEMORY.  Some callers may
  * rely on this. */
 enum parse_header_param
-parse_header_param(char *str, char *name, char **ret, int content_disposition)
+parse_header_param(char *str, const char *name, char **ret, int content_disposition)
 {
 	char *p = str;
 	int namelen, plen = 0;
diff --git a/src/protocol/header.h b/src/protocol/header.h
index af50c4adc..9cda13bd6 100644
--- a/src/protocol/header.h
+++ b/src/protocol/header.h
@@ -14,7 +14,7 @@ enum parse_header_param {
 };
 
 char *parse_header(char *, const char *, char **);
-enum parse_header_param parse_header_param(char *, char *, char **, int);
+enum parse_header_param parse_header_param(char *, const char *, char **, int);
 char *get_header_param(char *, char *);
 
 #ifdef __cplusplus