diff --git a/lib/rb/ext/strlcpy.c b/lib/rb/ext/strlcpy.c
index 3996950..6700ff2 100644
--- a/lib/rb/ext/strlcpy.c
+++ b/lib/rb/ext/strlcpy.c
@@ -17,11 +17,10 @@
  * under the License.
  */
 
-#include <string.h>
+#include "strlcpy.h"
 
 #ifndef HAVE_STRLCPY
 #define HAVE_STRLCPY
-
 size_t
 strlcpy (char *dst, const char *src, size_t dst_sz)
 {
@@ -38,7 +37,5 @@
       *(dst - 1) = '\0';
     return n + strlen (src);
 }
-#else
-extern size_t strlcpy(char *, const char *, size_t);
 #endif