diff --git a/desktop/kde/applications/kmbox/files/qt5.patch b/desktop/kde/applications/kmbox/files/qt5.patch
new file mode 100644
index 0000000000..913586ef6b
--- /dev/null
+++ b/desktop/kde/applications/kmbox/files/qt5.patch
@@ -0,0 +1,13 @@
+diff -Nuar a/src/mbox_p.cpp b/src/mbox_p.cpp
+--- a/src/mbox_p.cpp	2017-12-04 13:20:23.000000000 +0300
++++ b/src/mbox_p.cpp	2017-12-16 16:10:23.271073753 +0300
+@@ -157,7 +157,9 @@
+                 *d++ = '>';
+             }
+             // fall through
++#if QT_VERSION >= QT_VERSION_CHECK(5,8,0)
+             Q_FALLTHROUGH();
++#endif
+         default:
+             onlyAnglesAfterLF = false;
+             break;
diff --git a/desktop/kde/applications/kmbox/pspec.xml b/desktop/kde/applications/kmbox/pspec.xml
index 9f0d31dd64..74d08426c9 100644
--- a/desktop/kde/applications/kmbox/pspec.xml
+++ b/desktop/kde/applications/kmbox/pspec.xml
@@ -20,6 +20,9 @@
             <Dependency>kmime-devel</Dependency>
             <Dependency>boost-devel</Dependency>
         </BuildDependencies>
+        <Patches>
+            <Patch>qt5.patch</Patch>
+        </Patches>
     </Source>
 
     <Package>