Index: src/OFDNSResolver.h
==================================================================
--- src/OFDNSResolver.h
+++ src/OFDNSResolver.h
@@ -63,11 +63,13 @@
 	/*! The server returned an error that the domain does not exist */
 	OF_DNS_RESOLVER_ERROR_SERVER_NAME_ERROR,
 	/*! The server does not have support for the requested query */
 	OF_DNS_RESOLVER_ERROR_SERVER_NOT_IMPLEMENTED,
 	/*! The server refused the query */
-	OF_DNS_RESOLVER_ERROR_SERVER_REFUSED
+	OF_DNS_RESOLVER_ERROR_SERVER_REFUSED,
+	/*! There was no name server to query */
+	OF_DNS_RESOLVER_ERROR_NO_NAME_SERVER
 } of_dns_resolver_error_t;
 
 /*!
  * @protocol OFDNSResolverQueryDelegate OFDNSResolver.h ObjFW/OFDNSResolver.h
  *

Index: src/OFDNSResolver.m
==================================================================
--- src/OFDNSResolver.m
+++ src/OFDNSResolver.m
@@ -816,10 +816,21 @@
 		ID = [OFNumber numberWithUInt16: (uint16_t)of_random()];
 	} while ([_queries objectForKey: ID] != nil);
 
 	if (query.domainName.UTF8StringLength > 253)
 		@throw [OFOutOfRangeException exception];
+
+	if (_settings->_nameServers.count == 0) {
+		id exception = [OFDNSQueryFailedException
+		    exceptionWithQuery: query
+				 error: OF_DNS_RESOLVER_ERROR_NO_NAME_SERVER];
+		[delegate  resolver: self
+		    didPerformQuery: query
+			   response: nil
+			  exception: exception];
+		return;
+	}
 
 	context = [[[OFDNSResolverContext alloc]
 	    initWithQuery: query
 		       ID: ID
 		 settings: _settings
@@ -878,16 +889,14 @@
 
 	exception = [OFDNSQueryFailedException
 	    exceptionWithQuery: context->_query
 			 error: OF_DNS_RESOLVER_ERROR_TIMEOUT];
 
-	if ([context->_delegate respondsToSelector:
-	    @selector(resolver:didPerformQuery:response:exception:)])
-		[context->_delegate resolver: self
-			     didPerformQuery: context->_query
-				    response: nil
-				   exception: exception];
+	[context->_delegate resolver: self
+		     didPerformQuery: context->_query
+			    response: nil
+			   exception: exception];
 }
 
 - (bool)of_handleResponseBuffer: (unsigned char *)buffer
 			 length: (size_t)length
 			 sender: (const of_socket_address_t *)sender
@@ -1039,16 +1048,14 @@
 	}
 
 	if (exception != nil)
 		response = nil;
 
-	if ([context->_delegate respondsToSelector:
-	    @selector(resolver:didPerformQuery:response:exception:)])
-		[context->_delegate resolver: self
-			     didPerformQuery: context->_query
-				    response: response
-				   exception: exception];
+	[context->_delegate resolver: self
+		     didPerformQuery: context->_query
+			    response: response
+			   exception: exception];
 
 	return false;
 }
 
 -	  (bool)socket: (OFDatagramSocket *)sock
@@ -1273,18 +1280,16 @@
 
 		exception = [OFDNSQueryFailedException
 		    exceptionWithQuery: context->_query
 				 error: OF_DNS_RESOLVER_ERROR_CANCELED];
 
-		if ([context->_delegate respondsToSelector:
-		    @selector(resolver:didPerformQuery:response:exception:)])
-			[context->_delegate resolver: self
-				     didPerformQuery: context->_query
-					    response: nil
-					   exception: exception];
+		[context->_delegate resolver: self
+			     didPerformQuery: context->_query
+				    response: nil
+				   exception: exception];
 	}
 
 	[_queries removeAllObjects];
 
 	objc_autoreleasePoolPop(pool);
 }
 @end

Index: src/exceptions/OFDNSQueryFailedException.m
==================================================================
--- src/exceptions/OFDNSQueryFailedException.m
+++ src/exceptions/OFDNSQueryFailedException.m
@@ -42,10 +42,12 @@
 	case OF_DNS_RESOLVER_ERROR_SERVER_NOT_IMPLEMENTED:
 		return @"The server does not have support for the requested "
 		    @"query.";
 	case OF_DNS_RESOLVER_ERROR_SERVER_REFUSED:
 		return @"The server refused the query.";
+	case OF_DNS_RESOLVER_ERROR_NO_NAME_SERVER:
+		return @"There was no name server to query.";
 	default:
 		return @"Unknown error.";
 	}
 }