diff --git a/lib/smb.c b/lib/smb.c
index 0ddb167e61..09d09a3a99 100644
--- a/lib/smb.c
+++ b/lib/smb.c
@@ -27,6 +27,10 @@
 
 #if !defined(CURL_DISABLE_SMB) && defined(USE_CURL_NTLM_CORE)
 
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>  /* for htons() */
+#endif
+
 #include "smb.h"
 #include "url.h"
 #include "sendf.h"