diff --git a/federationsender/queue/destinationqueue.go b/federationsender/queue/destinationqueue.go
index 23294022a..c8d12e889 100644
--- a/federationsender/queue/destinationqueue.go
+++ b/federationsender/queue/destinationqueue.go
@@ -204,6 +204,7 @@ func (oq *destinationQueue) getPendingFromDatabase() {
 			}
 		} else {
 			logrus.WithError(err).Errorf("Failed to get pending PDUs for %q", oq.destination)
+			return
 		}
 	}
 	if eduCapacity := maxEDUsInMemory - len(oq.pendingEDUs); eduCapacity > 0 {
@@ -218,6 +219,7 @@ func (oq *destinationQueue) getPendingFromDatabase() {
 			}
 		} else {
 			logrus.WithError(err).Errorf("Failed to get pending EDUs for %q", oq.destination)
+			return
 		}
 	}
 	// If we've retrieved all of the events from the database with room to spare
@@ -326,20 +328,24 @@ func (oq *destinationQueue) backgroundSend() {
 			// If we successfully sent the transaction then clear out
 			// the pending events and EDUs, and wipe our transaction ID.
 			oq.statistics.Success()
-			oq.pendingMutex.Lock()
-			for i := range oq.pendingPDUs[:pc] {
-				oq.pendingPDUs[i] = nil
-			}
-			for i := range oq.pendingEDUs[:ec] {
-				oq.pendingEDUs[i] = nil
-			}
-			oq.pendingPDUs = oq.pendingPDUs[pc:]
-			oq.pendingEDUs = oq.pendingEDUs[ec:]
-			oq.pendingMutex.Unlock()
+			oq.deleteUpto(pc, ec)
 		}
 	}
 }
 
+func (oq *destinationQueue) deleteUpto(pc, ec int) {
+	oq.pendingMutex.Lock()
+	for i := range oq.pendingPDUs[:pc] {
+		oq.pendingPDUs[i] = nil
+	}
+	for i := range oq.pendingEDUs[:ec] {
+		oq.pendingEDUs[i] = nil
+	}
+	oq.pendingPDUs = nil
+	oq.pendingEDUs = nil
+	oq.pendingMutex.Unlock()
+}
+
 // nextTransaction creates a new transaction from the pending event
 // queue and sends it. Returns true if a transaction was sent or
 // false otherwise.