diff --git a/lib/roken/gai_strerror.c b/lib/roken/gai_strerror.c
index 15dbdb537..d07ddf163 100644
--- a/lib/roken/gai_strerror.c
+++ b/lib/roken/gai_strerror.c
@@ -65,7 +65,7 @@ static struct gai_error {
  *
  */
 
-char * ROKEN_LIB_FUNCTION
+const char * ROKEN_LIB_FUNCTION
 gai_strerror(int ecode)
 {
     struct gai_error *g;
diff --git a/lib/roken/roken.h.in b/lib/roken/roken.h.in
index c90b8c3b6..8c855d7a8 100644
--- a/lib/roken/roken.h.in
+++ b/lib/roken/roken.h.in
@@ -543,7 +543,7 @@ freeaddrinfo(struct addrinfo *);
 #endif
 
 #ifndef HAVE_GAI_STRERROR
-char * ROKEN_LIB_FUNCTION
+const char * ROKEN_LIB_FUNCTION
 gai_strerror(int);
 #endif