diff --git a/options.h b/options.h
index c61d4d9635e0f4e443b09e6776ea3b92ab6ec6b1..6b877621763c0e30baf5753508168ccf5bbf7b64 100644
--- a/options.h
+++ b/options.h
@@ -206,7 +206,10 @@ If you test it please contact the Dropbear author */
  * PAM challenge/response.
  * You can't enable both PASSWORD and PAM. */
 
+/* This requires crypt.h & crypt. */
+#ifdef HAVE_CRYPT_H
 #define ENABLE_SVR_PASSWORD_AUTH
+#endif
 /* PAM requires ./configure --enable-pam */
 /*#define ENABLE_SVR_PAM_AUTH */
 #define ENABLE_SVR_PUBKEY_AUTH