diff --git a/lib/identify.c b/lib/identify.c
index fbe2b7e..bd9221f 100644
--- a/lib/identify.c
+++ b/lib/identify.c
@@ -14,6 +14,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+#include <limits.h>
 #include <string.h>
 #include <stdlib.h>
 #include <math.h>