diff --git a/dtls.c b/dtls.c
index 86842f8..0a31e77 100644
--- a/dtls.c
+++ b/dtls.c
@@ -39,6 +39,11 @@
 /* OpenSSL doesn't deliberately export this, but we need it to
    workaround a DTLS bug in versions < 1.0.0e */
 extern void dtls1_stop_timer (SSL *);
+#elif OPENSSL_VERSION_NUMBER < 0x1000005fL && !defined(BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT)
+/* Just fucking shoot me now. I don't want to know how you fucked with your
+   OpenSSL today. No DTLS for you. */
+#warning Your OpenSSL is too bastardised for me to want to deal with it. Disabling DTLS.
+#undef SSL_OP_CISCO_ANYCONNECT
 #endif
 
 static unsigned char nybble(unsigned char n)