diff --git a/abstract_client.h b/abstract_client.h
--- a/abstract_client.h
+++ b/abstract_client.h
@@ -663,8 +663,7 @@
     enum ForceGeometry_t { NormalGeometrySet, ForceGeometrySet };
     void move(int x, int y, ForceGeometry_t force = NormalGeometrySet);
     void move(const QPoint &p, ForceGeometry_t force = NormalGeometrySet);
-    virtual void resizeWithChecks(int w, int h, ForceGeometry_t force = NormalGeometrySet) = 0;
-    void resizeWithChecks(const QSize& s, ForceGeometry_t force = NormalGeometrySet);
+    virtual void resizeWithChecks(const QSize &size, ForceGeometry_t force = NormalGeometrySet) = 0;
     void keepInArea(QRect area, bool partial = false);
     virtual QSize minSize() const;
     virtual QSize maxSize() const;
@@ -872,6 +871,14 @@
      */
     virtual bool supportsWindowRules() const;
 
+    /**
+     * Returns the extents of the server side-decoration.
+     *
+     * Note that the returned margins object will have all margins set to 0 if
+     * the client doesn't have a server side-decoration.
+     */
+    QMargins frameMargins() const;
+
 public Q_SLOTS:
     virtual void closeWindow() = 0;
 
@@ -1330,11 +1337,6 @@
     move(p.x(), p.y(), force);
 }
 
-inline void AbstractClient::resizeWithChecks(const QSize& s, AbstractClient::ForceGeometry_t force)
-{
-    resizeWithChecks(s.width(), s.height(), force);
-}
-
 inline const QList<AbstractClient*>& AbstractClient::transients() const
 {
     return m_transients;
diff --git a/abstract_client.cpp b/abstract_client.cpp
--- a/abstract_client.cpp
+++ b/abstract_client.cpp
@@ -808,9 +808,12 @@
         area.setBottom(qMax(area.bottom() + height() - 100, area.bottom()));
     }
     if (!partial) {
-        // resize to fit into area
-        if (area.width() < width() || area.height() < height())
-            resizeWithChecks(qMin(area.width(), width()), qMin(area.height(), height()));
+        // Resize to fit into area.
+        const QSize currentSize = size();
+        const QSize clampedSize = currentSize.boundedTo(area.size());
+        if (currentSize != clampedSize) {
+            resizeWithChecks(clampedSize);
+        }
     }
     int tx = x(), ty = y();
     if (geometry().right() > area.right() && width() <= area.width())
@@ -2092,4 +2095,9 @@
     return true;
 }
 
+QMargins AbstractClient::frameMargins() const
+{
+    return QMargins(borderLeft(), borderTop(), borderRight(), borderBottom());
+}
+
 }
diff --git a/client.h b/client.h
--- a/client.h
+++ b/client.h
@@ -181,8 +181,7 @@
     void plainResize(int w, int h, ForceGeometry_t force = NormalGeometrySet);
     void plainResize(const QSize& s, ForceGeometry_t force = NormalGeometrySet);
     /// resizeWithChecks() resizes according to gravity, and checks workarea position
-    using AbstractClient::resizeWithChecks;
-    void resizeWithChecks(int w, int h, ForceGeometry_t force = NormalGeometrySet) override;
+    void resizeWithChecks(const QSize &size, ForceGeometry_t force = NormalGeometrySet) override;
     void resizeWithChecks(int w, int h, xcb_gravity_t gravity, ForceGeometry_t force = NormalGeometrySet);
     void resizeWithChecks(const QSize& s, xcb_gravity_t gravity, ForceGeometry_t force = NormalGeometrySet);
     QSize sizeForClientSize(const QSize&, Sizemode mode = SizemodeAny, bool noframe = false) const override;
@@ -659,9 +658,9 @@
     plainResize(s.width(), s.height(), force);
 }
 
-inline void Client::resizeWithChecks(int w, int h, AbstractClient::ForceGeometry_t force)
+inline void Client::resizeWithChecks(const QSize &size, ForceGeometry_t force)
 {
-    resizeWithChecks(w, h, XCB_GRAVITY_BIT_FORGET, force);
+    resizeWithChecks(size, XCB_GRAVITY_BIT_FORGET, force);
 }
 
 inline void Client::resizeWithChecks(const QSize& s, xcb_gravity_t gravity, ForceGeometry_t force)
diff --git a/geometry.cpp b/geometry.cpp
--- a/geometry.cpp
+++ b/geometry.cpp
@@ -1932,21 +1932,19 @@
     // Such code is wrong and should be changed to handle the case when the window is shaded,
     // for example using Client::clientSize()
 
-    const QMargins frameMargins(borderLeft(), borderTop(), borderRight(), borderBottom());
-
     QRect geometry = rect;
 
     if (shade_geometry_change)
         ; // nothing
     else if (isShade()) {
         if (geometry.height() == borderTop() + borderBottom()) {
             qCDebug(KWIN_CORE) << "Shaded geometry passed for size:";
         } else {
-            client_size = rect.marginsRemoved(frameMargins).size();
+            client_size = rect.marginsRemoved(frameMargins()).size();
             geometry.setHeight(borderTop() + borderBottom());
         }
     } else {
-        client_size = rect.marginsRemoved(frameMargins).size();
+        client_size = rect.marginsRemoved(frameMargins()).size();
     }
     if (!areGeometryUpdatesBlocked() && geometry != rules()->checkGeometry(geometry)) {
         qCDebug(KWIN_CORE) << "forced geometry fail:" << geometry << ":" << rules()->checkGeometry(geometry);
diff --git a/internal_client.h b/internal_client.h
--- a/internal_client.h
+++ b/internal_client.h
@@ -57,8 +57,7 @@
     bool isInputMethod() const override;
     bool isOutline() const override;
     quint32 windowId() const override;
-    using AbstractClient::resizeWithChecks;
-    void resizeWithChecks(int w, int h, ForceGeometry_t force = NormalGeometrySet) override;
+    void resizeWithChecks(const QSize &size, ForceGeometry_t force = NormalGeometrySet) override;
     QWindow *internalWindow() const override;
     bool supportsWindowRules() const override;
 
diff --git a/internal_client.cpp b/internal_client.cpp
--- a/internal_client.cpp
+++ b/internal_client.cpp
@@ -297,21 +297,19 @@
     }
 }
 
-void InternalClient::resizeWithChecks(int w, int h, ForceGeometry_t force)
+void InternalClient::resizeWithChecks(const QSize &size, ForceGeometry_t force)
 {
     Q_UNUSED(force)
+
     if (!m_internalWindow) {
         return;
     }
-    QRect area = workspace()->clientArea(WorkArea, this);
-    // don't allow growing larger than workarea
-    if (w > area.width()) {
-        w = area.width();
-    }
-    if (h > area.height()) {
-        h = area.height();
-    }
-    m_internalWindow->setGeometry(QRect(pos() + QPoint(borderLeft(), borderTop()), QSize(w, h) - QSize(borderLeft() + borderRight(), borderTop() + borderBottom())));
+
+    // Don't allow growing larger than workarea.
+    const QRect workArea = workspace()->clientArea(WorkArea, this);
+    const QSize clampedSize = size.boundedTo(workArea.size());
+
+    m_internalWindow->setGeometry(QRect(pos(), clampedSize) - frameMargins());
 }
 
 void InternalClient::doResizeSync()
diff --git a/shell_client.h b/shell_client.h
--- a/shell_client.h
+++ b/shell_client.h
@@ -105,8 +105,7 @@
     bool userCanSetNoBorder() const override;
     bool wantsInput() const override;
     bool dockWantsInput() const override;
-    using AbstractClient::resizeWithChecks;
-    void resizeWithChecks(int w, int h, ForceGeometry_t force = NormalGeometrySet) override;
+    void resizeWithChecks(const QSize &size, ForceGeometry_t force = NormalGeometrySet) override;
     void setGeometry(const QRect &rect, ForceGeometry_t force = NormalGeometrySet) override;
     bool hasStrut() const override;
 
diff --git a/shell_client.cpp b/shell_client.cpp
--- a/shell_client.cpp
+++ b/shell_client.cpp
@@ -1259,22 +1259,19 @@
     setFullScreen(fullScreen, false);
 }
 
-void ShellClient::resizeWithChecks(int w, int h, ForceGeometry_t force)
+void ShellClient::resizeWithChecks(const QSize &size, ForceGeometry_t force)
 {
     Q_UNUSED(force)
-    QRect area = workspace()->clientArea(WorkArea, this);
-    // don't allow growing larger than workarea
-    if (w > area.width()) {
-        w = area.width();
-    }
-    if (h > area.height()) {
-        h = area.height();
-    }
+
+    // Don't allow growing larger than workarea.
+    const QRect workArea = workspace()->clientArea(WorkArea, this);
+    const QSize clampedSize = size.boundedTo(workArea.size());
+
     if (m_shellSurface) {
-        m_shellSurface->requestSize(QSize(w, h));
+        m_shellSurface->requestSize(clampedSize);
     }
     if (m_xdgShellSurface) {
-        m_xdgShellSurface->configure(xdgSurfaceStates(), QSize(w, h));
+        m_xdgShellSurface->configure(xdgSurfaceStates(), clampedSize);
     }
 }