diff --git a/0001-Add-the-missing-cassert-include.patch b/0001-Add-the-missing-cassert-include.patch
new file mode 100644
index 0000000..bdb384c
--- /dev/null
+++ b/0001-Add-the-missing-cassert-include.patch
@@ -0,0 +1,37 @@
+From dec30fec70d9ec9bcb52372b054d0d409f8c3075 Mon Sep 17 00:00:00 2001
+From: Christophe Giboudeaux <christophe@krop.fr>
+Date: Mon, 13 Jan 2020 13:50:23 +0100
+Subject: [PATCH] Add the missing cassert include
+
+---
+ src/kdirtreeview.cpp | 1 +
+ src/ktreemaptile.cpp | 1 +
+ 2 files changed, 2 insertions(+)
+
+diff --git a/src/kdirtreeview.cpp b/src/kdirtreeview.cpp
+index 808d20a..88b2ee3 100644
+--- a/src/kdirtreeview.cpp
++++ b/src/kdirtreeview.cpp
+@@ -7,6 +7,7 @@
+ 
+ #include <stdlib.h>
+ #include <time.h>
++#include <cassert>
+ 
+ #include <QDesktopServices>
+ #include <QHeaderView>
+diff --git a/src/ktreemaptile.cpp b/src/ktreemaptile.cpp
+index 3c140eb..27c4632 100644
+--- a/src/ktreemaptile.cpp
++++ b/src/ktreemaptile.cpp
+@@ -6,6 +6,7 @@
+ 
+ #include <QDebug>
+ #include <algorithm>
++#include <cassert>
+ #include <math.h>
+ #include <qimage.h>
+ #include <qpainter.h>
+-- 
+2.24.1
+
diff --git a/k4dirstat.changes b/k4dirstat.changes
index b87ec75..ca2633b 100644
--- a/k4dirstat.changes
+++ b/k4dirstat.changes
@@ -6,6 +6,8 @@ Mon Jan 13 12:35:34 UTC 2020 - Christophe Giboudeaux <christophe@krop.fr>
     multi-selection
   * 'Open in terminal' now open Konsole in the selected folder
   * Move from bitbucket to github
+- Add patch to fix build on Leap 15.1
+  * 0001-Add-the-missing-cassert-include.patch
 
 -------------------------------------------------------------------
 Tue Apr  2 15:30:22 UTC 2019 - Christophe Giboudeaux <christophe@krop.fr>
diff --git a/k4dirstat.spec b/k4dirstat.spec
index b57fa33..7693d04 100644
--- a/k4dirstat.spec
+++ b/k4dirstat.spec
@@ -24,6 +24,8 @@ License:        GPL-2.0-only AND LGPL-2.0-only
 Group:          Productivity/File utilities
 URL:            https://github.com/jeromerobert/k4dirstat
 Source0:        https://github.com/jeromerobert/k4dirstat/archive/%{version}.tar.gz#/%{name}-%{version}.tar.gz
+# PATCH-FIX-UPSTREAM
+Patch0:         0001-Add-the-missing-cassert-include.patch
 BuildRequires:  kf5-filesystem
 BuildRequires:  zlib-devel
 BuildRequires:  cmake(KF5CoreAddons)
@@ -50,7 +52,7 @@ graphically.
 %lang_package
 
 %prep
-%setup -q
+%autosetup -p1
 
 %build
 %cmake_kf5 -d build