diff --git a/src/DNS_Mgr.cc b/src/DNS_Mgr.cc
index 4edff2088c..c52e6086f4 100644
--- a/src/DNS_Mgr.cc
+++ b/src/DNS_Mgr.cc
@@ -1407,12 +1407,15 @@ void DNS_Mgr::DoProcess()
 		if ( req->time + DNS_TIMEOUT > current_time() )
 			break;
 
-		if ( req->IsAddrReq() )
-			CheckAsyncAddrRequest(req->host, true);
-		else if ( req->is_txt )
-			CheckAsyncTextRequest(req->name.c_str(), true);
-		else
-			CheckAsyncHostRequest(req->name.c_str(), true);
+		if ( ! req->processed )
+			{
+			if ( req->IsAddrReq() )
+				CheckAsyncAddrRequest(req->host, true);
+			else if ( req->is_txt )
+				CheckAsyncTextRequest(req->name.c_str(), true);
+			else
+				CheckAsyncHostRequest(req->name.c_str(), true);
+			}
 
 		asyncs_timeouts.pop();
 		delete req;
diff --git a/src/DNS_Mgr.h b/src/DNS_Mgr.h
index 5aac420303..9f9fe4ccc3 100644
--- a/src/DNS_Mgr.h
+++ b/src/DNS_Mgr.h
@@ -172,12 +172,13 @@ protected:
 
 	struct AsyncRequest {
 		double time;
+		bool is_txt;
+		bool processed;
 		IPAddr host;
 		string name;
-		bool is_txt;
 		CallbackList callbacks;
 
-		AsyncRequest() : time(0.0), is_txt(false) { }
+		AsyncRequest() : time(0.0), is_txt(false), processed(false) { }
 
 		bool IsAddrReq() const	{ return name.length() == 0; }
 
@@ -190,6 +191,7 @@ protected:
 				delete *i;
 				}
 			callbacks.clear();
+			processed = true;
 			}
 
 		void Resolved(TableVal* addrs)
@@ -201,6 +203,7 @@ protected:
 				delete *i;
 				}
 			callbacks.clear();
+			processed = true;
 			}
 
 		void Timeout()
@@ -212,6 +215,7 @@ protected:
 				delete *i;
 				}
 			callbacks.clear();
+			processed = true;
 			}
 
 	};