- [Makefile umac.c] Add special-case target to build umac128.o.
diff --git a/umac.c b/umac.c
index e78d2cc..e373de5 100644
--- a/umac.c
+++ b/umac.c
@@ -52,7 +52,9 @@
 /* --- User Switches ---------------------------------------------------- */
 /* ---------------------------------------------------------------------- */
 
+#ifndef UMAC_OUTPUT_LEN
 #define UMAC_OUTPUT_LEN     8  /* Alowable: 4, 8, 12, 16                  */
+#endif
 /* #define FORCE_C_ONLY        1  ANSI C and 64-bit integers req'd        */
 /* #define AES_IMPLEMENTAION   1  1 = OpenSSL, 2 = Barreto, 3 = Gladman   */
 /* #define SSE2                0  Is SSE2 is available?                   */