diff --git a/src/libs/ssh/sshchannelmanager.cpp b/src/libs/ssh/sshchannelmanager.cpp
index 409f2a586f3..74fe368885f 100644
--- a/src/libs/ssh/sshchannelmanager.cpp
+++ b/src/libs/ssh/sshchannelmanager.cpp
@@ -178,12 +178,14 @@ void SshChannelManager::insertChannel(AbstractSshChannel *priv,
     m_sessions.insert(priv, pub);
 }
 
-void SshChannelManager::closeAllChannels()
+int SshChannelManager::closeAllChannels()
 {
+    const int count = m_channels.count();
     for (ChannelIterator it = m_channels.begin(); it != m_channels.end(); ++it)
         it.value()->closeChannel();
     m_channels.clear();
     m_sessions.clear();
+    return count;
 }
 
 void SshChannelManager::removeChannel(ChannelIterator it)
diff --git a/src/libs/ssh/sshchannelmanager_p.h b/src/libs/ssh/sshchannelmanager_p.h
index 9cc88e9dd68..6ef4a406a06 100644
--- a/src/libs/ssh/sshchannelmanager_p.h
+++ b/src/libs/ssh/sshchannelmanager_p.h
@@ -57,7 +57,7 @@ public:
     QSharedPointer<SshRemoteProcess> createRemoteProcess(const QByteArray &command);
     QSharedPointer<SshRemoteProcess> createRemoteShell();
     QSharedPointer<SftpChannel> createSftpChannel();
-    void closeAllChannels();
+    int closeAllChannels();
 
     void handleChannelRequest(const SshIncomingPacket &packet);
     void handleChannelOpen(const SshIncomingPacket &packet);
diff --git a/src/libs/ssh/sshconnection.cpp b/src/libs/ssh/sshconnection.cpp
index 21cc7f57538..0337563c80d 100644
--- a/src/libs/ssh/sshconnection.cpp
+++ b/src/libs/ssh/sshconnection.cpp
@@ -193,6 +193,15 @@ QSharedPointer<SftpChannel> SshConnection::createSftpChannel()
     return d->createSftpChannel();
 }
 
+int SshConnection::closeAllChannels()
+{
+    try {
+        return d->m_channelManager->closeAllChannels();
+    } catch (const Botan::Exception &e) {
+        qDebug("%s: %s", Q_FUNC_INFO, e.what());
+        return -1;
+    }
+}
 
 namespace Internal {
 
diff --git a/src/libs/ssh/sshconnection.h b/src/libs/ssh/sshconnection.h
index 5354ec59463..5f70c282f57 100644
--- a/src/libs/ssh/sshconnection.h
+++ b/src/libs/ssh/sshconnection.h
@@ -106,6 +106,9 @@ public:
     QSharedPointer<SshRemoteProcess> createRemoteShell();
     QSharedPointer<SftpChannel> createSftpChannel();
 
+    // -1 if an error occurred, number of channels closed otherwise.
+    int closeAllChannels();
+
 signals:
     void connected();
     void disconnected();
diff --git a/src/libs/ssh/sshconnectionmanager.cpp b/src/libs/ssh/sshconnectionmanager.cpp
index 114b5200867..dc62c9eeb7f 100644
--- a/src/libs/ssh/sshconnectionmanager.cpp
+++ b/src/libs/ssh/sshconnectionmanager.cpp
@@ -145,10 +145,15 @@ public:
                     break;
                 }
             }
-            if (!haveConnection)
+            if (!haveConnection) {
+                // Let's nag clients who release connections with open channels.
+                const int channelCount = connection->closeAllChannels();
+                QSSH_ASSERT(channelCount == 0);
+
                 m_unacquiredConnections.append(connection);
-            else
+            } else {
                 doDelete = true;
+            }
         }
 
         if (doDelete) {