--- a/src/gsm2vmo.c
+++ b/src/gsm2vmo.c
@@ -27,7 +27,7 @@
  * 12 bit header and 260 bits standard GSM frame, as described
  * in GSM 06.10 and GSM 06.12. The header is 0x2010 always.
  */
-
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
--- a/src/vmo2gsm.c
+++ b/src/vmo2gsm.c
@@ -27,7 +27,7 @@
  * 12 bit header and 260 bits standart GSM frame, as described
  * in GSM 06.10 and GSM 06.12. The header is 0x2010 always.
  */
-
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>