diff --git a/kit/ChildSession.cpp b/kit/ChildSession.cpp
index b1bee8ccf..371bc4cd4 100644
--- a/kit/ChildSession.cpp
+++ b/kit/ChildSession.cpp
@@ -248,6 +248,10 @@ bool ChildSession::_handleInput(const char *buffer, int length)
     {
         return renderWindow(buffer, length, tokens);
     }
+    else if (tokens[0] == "resizewindow")
+    {
+        return resizeWindow(buffer, length, tokens);
+    }
     else if (tokens[0] == "tile" || tokens[0] == "tilecombine")
     {
         assert(false && "Tile traffic should go through the DocumentBroker-LoKit WS.");
@@ -1489,6 +1493,26 @@ bool ChildSession::renderWindow(const char* /*buffer*/, int /*length*/, const st
     return true;
 }
 
+bool ChildSession::resizeWindow(const char* /*buffer*/, int /*length*/, const std::vector<std::string>& tokens)
+{
+    const unsigned winId = (tokens.size() > 1 ? std::stoul(tokens[1].c_str(), nullptr, 10) : 0);
+
+    getLOKitDocument()->setView(_viewId);
+
+    std::string size;
+    if (tokens.size() > 2 && getTokenString(tokens[2], "size", size))
+    {
+        const std::vector<int> sizeParts = LOOLProtocol::tokenizeInts(size, ',');
+        if (sizeParts.size() == 2)
+        {
+            getLOKitDocument()->resizeWindow(winId, sizeParts[0], sizeParts[1]);
+            return true;
+        }
+    }
+
+    LOG_WRN("resizewindow command doesn't specify sensible size= attribute.");
+    return true;
+}
 
 bool ChildSession::sendWindowCommand(const char* /*buffer*/, int /*length*/, const std::vector<std::string>& tokens)
 {
diff --git a/kit/ChildSession.hpp b/kit/ChildSession.hpp
index bd0d12a1c..cbaaba54b 100644
--- a/kit/ChildSession.hpp
+++ b/kit/ChildSession.hpp
@@ -261,6 +261,7 @@ private:
     bool selectText(const char* buffer, int length, const std::vector<std::string>& tokens);
     bool selectGraphic(const char* buffer, int length, const std::vector<std::string>& tokens);
     bool renderWindow(const char* buffer, int length, const std::vector<std::string>& tokens);
+    bool resizeWindow(const char* buffer, int length, const std::vector<std::string>& tokens);
     bool resetSelection(const char* buffer, int length, const std::vector<std::string>& tokens);
     bool saveAs(const char* buffer, int length, const std::vector<std::string>& tokens);
     bool setClientPart(const char* buffer, int length, const std::vector<std::string>& tokens);
diff --git a/kit/Kit.cpp b/kit/Kit.cpp
index a167ae513..beebb8aa2 100644
--- a/kit/Kit.cpp
+++ b/kit/Kit.cpp
@@ -2279,7 +2279,7 @@ protected:
             document.reset();
         }
         else if (tokens[0] == "tile" || tokens[0] == "tilecombine" || tokens[0] == "canceltiles" ||
-                tokens[0] == "paintwindow" ||
+                tokens[0] == "paintwindow" || tokens[0] == "resizewindow" ||
                 LOOLProtocol::getFirstToken(tokens[0], '-') == "child")
         {
             if (document)
diff --git a/wsd/ClientSession.cpp b/wsd/ClientSession.cpp
index 328d1d1fc..2623f3585 100644
--- a/wsd/ClientSession.cpp
+++ b/wsd/ClientSession.cpp
@@ -425,7 +425,8 @@ bool ClientSession::_handleInput(const char *buffer, int length)
              tokens[0] != "exportsignanduploaddocument" &&
              tokens[0] != "rendershapeselection" &&
              tokens[0] != "removesession" &&
-             tokens[0] != "renamefile")
+             tokens[0] != "renamefile" &&
+             tokens[0] != "resizewindow")
     {
         LOG_ERR("Session [" << getId() << "] got unknown command [" << tokens[0] << "].");
         sendTextFrame("error: cmd=" + tokens[0] + " kind=unknown");
@@ -1118,7 +1119,7 @@ bool ClientSession::handleKitToClientMessage(const char* buffer, const int lengt
             }
             else
                 return false;
-        }
+         }
     }
 #if !MOBILEAPP
     else if (tokens.size() == 3 && tokens[0] == "saveas:")