diff --git a/wsd/ClientSession.cpp b/wsd/ClientSession.cpp
index 4a61bbe49..299cba324 100644
--- a/wsd/ClientSession.cpp
+++ b/wsd/ClientSession.cpp
@@ -1079,6 +1079,16 @@ void ClientSession::removeOutdatedTilesOnFly()
     }
 }
 
+Util::Rectangle ClientSession::getNormalizedVisibleArea() const
+{
+    Util::Rectangle normalizedVisArea;
+    normalizedVisArea._x1 = std::max(_clientVisibleArea._x1, 0);
+    normalizedVisArea._y1 = std::max(_clientVisibleArea._y1, 0);
+    normalizedVisArea._x2 = _clientVisibleArea._x2;
+    normalizedVisArea._y2 = _clientVisibleArea._y2;
+    return normalizedVisArea;
+}
+
 void ClientSession::onDisconnect()
 {
     LOG_INF(getName() << " Disconnected, current number of connections: " << LOOLWSD::NumConnections);
@@ -1172,12 +1182,8 @@ void ClientSession::handleTileInvalidation(const std::string& message,
         return;
     }
 
-    // Visible area can have negativ value as position, but we have tiles only in the positiv range 
-    Util::Rectangle normalizedVisArea;
-    normalizedVisArea._x1 = std::max(_clientVisibleArea._x1, 0);
-    normalizedVisArea._y1 = std::max(_clientVisibleArea._y1, 0);
-    normalizedVisArea._x2 = _clientVisibleArea._x2;
-    normalizedVisArea._y2 = _clientVisibleArea._y2;
+    // Visible area can have negativ value as position, but we have tiles only in the positive range
+    Util::Rectangle normalizedVisArea = getNormalizedVisibleArea();
 
     std::pair<int, Util::Rectangle> result = TileCache::parseInvalidateMsg(message);
     int part = result.first;
diff --git a/wsd/ClientSession.hpp b/wsd/ClientSession.hpp
index b4835cfd9..2efd26624 100644
--- a/wsd/ClientSession.hpp
+++ b/wsd/ClientSession.hpp
@@ -130,6 +130,9 @@ public:
     void removeOutdatedTilesOnFly();
 
     Util::Rectangle getVisibleArea() const { return _clientVisibleArea; }
+    /// Visible area can have negative value as position, but we have tiles only in the positive range
+    Util::Rectangle getNormalizedVisibleArea() const;
+
     int getTileWidthInTwips() const { return _tileWidthTwips; }
     int getTileHeightInTwips() const { return _tileHeightTwips; }
 
diff --git a/wsd/DocumentBroker.cpp b/wsd/DocumentBroker.cpp
index 310eac031..59ce6d0b8 100644
--- a/wsd/DocumentBroker.cpp
+++ b/wsd/DocumentBroker.cpp
@@ -1368,13 +1368,15 @@ void DocumentBroker::sendRequestedTiles(const std::shared_ptr<ClientSession>& se
     std::unique_lock<std::mutex> lock(_mutex);
 
     // How many tiles we have on the visible area, set the upper limit accordingly
-    const float tilesFitOnWidth = static_cast<float>(session->getVisibleArea().getWidth()) /
-                                  static_cast<float>(session->getTileWidthInTwips());
-    const float tilesFitOnHeight = static_cast<float>(session->getVisibleArea().getHeight()) /
-                                   static_cast<float>(session->getTileHeightInTwips());
-    const float tilesInVisArea = tilesFitOnWidth * tilesFitOnHeight;
+    Util::Rectangle normalizedVisArea = session->getNormalizedVisibleArea();
 
-    const float tilesOnFlyUpperLimit = std::max(TILES_ON_FLY_MIN_UPPER_LIMIT, tilesInVisArea * 1.20f);
+    const int tilesFitOnWidth = std::ceil(normalizedVisArea._x2 / session->getTileWidthInTwips()) -
+                                std::ceil(normalizedVisArea._x1 / session->getTileWidthInTwips()) + 1;
+    const int tilesFitOnHeight = std::ceil(normalizedVisArea._y2 / session->getTileHeightInTwips()) -
+                                 std::ceil(normalizedVisArea._y1 / session->getTileHeightInTwips()) + 1;
+    const int tilesInVisArea = tilesFitOnWidth * tilesFitOnHeight;
+
+    const float tilesOnFlyUpperLimit = std::max(TILES_ON_FLY_MIN_UPPER_LIMIT, tilesInVisArea * 1.5f);
 
     // Update client's tilesBeingRendered list
     session->removeOutdatedTileSubscriptions();