diff --git a/str.c b/str.c
index 28202638..aa235cfc 100644
--- a/str.c
+++ b/str.c
@@ -88,7 +88,7 @@ char *str_toupper_inplace(char *str)
   return str;
 }
 
-int strnchr(const char *s, size_t n, char c)
+const char *strnchr(const char *s, size_t n, char c)
 {
   for (; n; --n, ++s) {
     if (*s == c)
diff --git a/str.h b/str.h
index c94fef1b..9c8f15e0 100644
--- a/str.h
+++ b/str.h
@@ -91,7 +91,7 @@ size_t str_fromprint(unsigned char *dst, const char *src);
  *
  * @author Andrew Bettison <andrew@servalproject.com>
  */
-int strnchr(const char *s, size_t n, char c);
+const char *strnchr(const char *s, size_t n, char c);
 
 /* Check if a given nul-terminated string 'str' starts with a given nul-terminated sub-string.  If
  * so, return 1 and, if afterp is not NULL, set *afterp to point to the character in 'str'