diff --git a/src/enc.h b/src/enc.h
index 55d49bb..edf8f6b 100644
--- a/src/enc.h
+++ b/src/enc.h
@@ -454,8 +454,10 @@ extern void enc_do(char *ciph, char *keyfile, char *lport, char *rhp) {
 		p++;
 		if (strstr(p, "md5+") == p) {
 			Digest = EVP_md5();        p += strlen("md5+");
+#ifndef OPENSSL_NO_SHA0
 		} else if (strstr(p, "sha+") == p) {
 			Digest = EVP_sha();        p += strlen("sha+");
+#endif
 		} else if (strstr(p, "sha1+") == p) {
 			Digest = EVP_sha1();       p += strlen("sha1+");
 		} else if (strstr(p, "ripe+") == p) {