Index: src/concatkdf.c
--- src/concatkdf.c.orig
+++ src/concatkdf.c
@@ -14,7 +14,7 @@
 #include <malloc.h>
 #else
 #include <arpa/inet.h>
-#include <alloca.h>
+#include <stdlib.h>
 #endif
 #include <openssl/evp.h>
 #include <string.h>
