diff --git a/0001-Use-custom-QScrollArea-with-size-hint-not-limited-by.patch b/0001-Use-custom-QScrollArea-with-size-hint-not-limited-by.patch
new file mode 100644
index 0000000..0a4bdf9
--- /dev/null
+++ b/0001-Use-custom-QScrollArea-with-size-hint-not-limited-by.patch
@@ -0,0 +1,87 @@
+From 23ba2b37ef825f0efccc169455f45b0dcdac97cf Mon Sep 17 00:00:00 2001
+From: Valeriy Malov <jazzvoid@gmail.com>
+Date: Wed, 8 Aug 2018 16:42:00 +0300
+Subject: [PATCH] Use custom QScrollArea with size hint not limited by font
+ size
+
+Summary:
+For some reason original QScrollArea has constraint on a size hint
+This causes large KCMShell pages open in relatively small windows,
+because QScrollArea inside reports small size hint
+
+BUG: 389585
+
+Test Plan:
+patched 5.48.0 with this, tested networkmanager and few other kcms,
+they now seem to open in full size (except for kscreen which has custom sizehint,
+it probably needs size hint for the QML area specifically, not the whole window;
+and except for opengl that has it's own scrollable area which needs a size hint too)
+
+Reviewers: #frameworks, ngraham
+
+Reviewed By: ngraham
+
+Subscribers: ngraham, kde-frameworks-devel
+
+Tags: #frameworks
+
+Differential Revision: https://phabricator.kde.org/D14692
+---
+ src/kcmultidialog.cpp |  2 +-
+ src/kcmultidialog.h   | 22 ++++++++++++++++++++++
+ 2 files changed, 23 insertions(+), 1 deletion(-)
+
+diff --git a/src/kcmultidialog.cpp b/src/kcmultidialog.cpp
+index 6526efb..d5f2f10 100644
+--- a/src/kcmultidialog.cpp
++++ b/src/kcmultidialog.cpp
+@@ -425,7 +425,7 @@ KPageWidgetItem *KCMultiDialog::addModule(const KCModuleInfo &moduleInfo,
+     }
+ 
+     // Create the scroller
+-    QScrollArea *moduleScroll = new QScrollArea(this);
++    auto *moduleScroll = new UnboundScrollArea(this);
+     // Prepare the scroll area
+     moduleScroll->setWidgetResizable(true);
+     moduleScroll->setFrameStyle(QFrame::NoFrame);
+diff --git a/src/kcmultidialog.h b/src/kcmultidialog.h
+index c405dc3..2073be5 100644
+--- a/src/kcmultidialog.h
++++ b/src/kcmultidialog.h
+@@ -23,6 +23,8 @@
+ #ifndef KCMULTIDIALOG_H
+ #define KCMULTIDIALOG_H
+ 
++#include <QScrollArea>
++
+ #include <kcmoduleinfo.h>
+ #include <kpagedialog.h>
+ 
+@@ -180,4 +182,24 @@ private:
+     Q_PRIVATE_SLOT(d_func(), void _k_updateHeader(bool use, const QString &message))
+ };
+ 
++/**
++ * @brief Custom QScrollArea class that doesn't limit its size hint
++ *
++ * See original QScrollArea::sizeHint() function,
++ * where the size hint is bound by 36*24 font heights
++ *
++ * Workaround for https://bugreports.qt.io/browse/QTBUG-10459
++ */
++
++class UnboundScrollArea : public QScrollArea {
++    Q_OBJECT
++public:
++    QSize sizeHint() const override {
++        return widget() ? widget()->sizeHint() : QSize();
++    }
++
++    UnboundScrollArea(QWidget * w) : QScrollArea(w) {}
++    virtual ~UnboundScrollArea() = default;
++};
++
+ #endif
+-- 
+2.18.0
+
diff --git a/kcmutils.changes b/kcmutils.changes
index e81cb21..766de79 100644
--- a/kcmutils.changes
+++ b/kcmutils.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Tue Aug 28 16:49:02 UTC 2018 - fabian@ritter-vogt.de
+
+- Add patch to fix default size of kcms (kde#389585):
+  * 0001-Use-custom-QScrollArea-with-size-hint-not-limited-by.patch
+
 -------------------------------------------------------------------
 Tue Aug 21 10:19:23 UTC 2018 - jengelh@inai.de
 
diff --git a/kcmutils.spec b/kcmutils.spec
index 27339e5..27a42df 100644
--- a/kcmutils.spec
+++ b/kcmutils.spec
@@ -32,6 +32,8 @@ Group:          System/GUI/KDE
 URL:            http://www.kde.org
 Source:         http://download.kde.org/stable/frameworks/%{_tar_path}/%{name}-%{version}.tar.xz
 Source1:        baselibs.conf
+# PATCH-FIX-UPSTREAM
+Patch1:         0001-Use-custom-QScrollArea-with-size-hint-not-limited-by.patch
 BuildRequires:  cmake >= 3.0
 BuildRequires:  extra-cmake-modules >= %{_kf5_bugfix_version}
 BuildRequires:  fdupes
@@ -83,6 +85,7 @@ created with the KConfigWidgets framework. Development files.
 
 %prep
 %setup -q
+%autopatch -p1
 
 %build
   %cmake_kf5 -d build