Index: src/OFTLSSocket.h
==================================================================
--- src/OFTLSSocket.h
+++ src/OFTLSSocket.h
@@ -80,11 +80,11 @@
  *	 a TCP socket which is already connected!
  *
  * @param host The host to expect for certificate verification.
  *	       May be nil if certificate verification is disabled.
  */
-- (void)startTLSWithExpectedHost: (OFString*)host;
+- (void)startTLSWithExpectedHost: (nullable OFString*)host;
 
 /*!
  * @brief Sets a delegate for the TLS socket.
  *
  * @param delegate The delegate to use