diff --git a/gnu/local.mk b/gnu/local.mk
index bb333a6611..ea066aa718 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -1093,7 +1093,6 @@ dist_patch_DATA =						\
   %D%/packages/patches/qtoctave-qt-5.11-fix.patch		\
   %D%/packages/patches/qtscript-disable-tests.patch		\
   %D%/packages/patches/quagga-reproducible-build.patch          \
-  %D%/packages/patches/quassel-qt-5.11.patch			\
   %D%/packages/patches/quickswitch-fix-dmenu-check.patch	\
   %D%/packages/patches/rapicorn-isnan.patch			\
   %D%/packages/patches/raptor2-heap-overflow.patch		\
diff --git a/gnu/packages/irc.scm b/gnu/packages/irc.scm
index 5a1df6d600..4f4e494ee5 100644
--- a/gnu/packages/irc.scm
+++ b/gnu/packages/irc.scm
@@ -74,7 +74,6 @@ (define-public quassel
         (sha256
          (base32
           "1qkl3sb4ijx4k17m0c42j2p5bc4jymypwhmplm942rbrzm6mg50q"))
-        (patches (search-patches "quassel-qt-5.11.patch"))
         (modules '((guix build utils)))
         ;; We don't want to install the bundled scripts.
         (snippet
diff --git a/gnu/packages/patches/quassel-qt-5.11.patch b/gnu/packages/patches/quassel-qt-5.11.patch
deleted file mode 100644
index 545f8b7610..0000000000
--- a/gnu/packages/patches/quassel-qt-5.11.patch
+++ /dev/null
@@ -1,72 +0,0 @@
-https://github.com/quassel/quassel/commit/92f4dca367c3a6f0536a1e0f3fbb44bb6ed4da62.patch
-This can be removed after quassel 0.12.5.
-
-From 92f4dca367c3a6f0536a1e0f3fbb44bb6ed4da62 Mon Sep 17 00:00:00 2001
-From: Manuel Nickschas <sputnick@quassel-irc.org>
-Date: Thu, 3 May 2018 23:19:34 +0200
-Subject: [PATCH] cmake: Fix build with Qt 5.11
-
-Qt 5.11 removes the qt5_use_modules function, so add a copy. If
-present, the Qt-provided function will be used instead.
-
-Closes GH-355.
----
- cmake/QuasselMacros.cmake | 38 ++++++++++++++++++++++++++++++++++++++
- 1 file changed, 38 insertions(+)
-
-diff --git a/cmake/QuasselMacros.cmake b/cmake/QuasselMacros.cmake
-index 652c0042d..d77ba1cfb 100644
---- a/cmake/QuasselMacros.cmake
-+++ b/cmake/QuasselMacros.cmake
-@@ -5,6 +5,9 @@
- # The qt4_use_modules function was taken from CMake's Qt4Macros.cmake:
- # (C) 2005-2009 Kitware, Inc.
- #
-+# The qt5_use_modules function was taken from Qt 5.10.1 (and modified):
-+# (C) 2005-2011 Kitware, Inc.
-+#
- # Redistribution and use is allowed according to the terms of the BSD license.
- # For details see the accompanying COPYING-CMAKE-SCRIPTS file.
- 
-@@ -43,6 +46,41 @@ function(qt4_use_modules _target _link_type)
-     endforeach()
- endfunction()
- 
-+# Qt 5.11 removed the qt5_use_modules function, so we need to provide it until we can switch to a modern CMake version.
-+# If present, the Qt-provided version will be used automatically instead.
-+function(qt5_use_modules _target _link_type)
-+    if (NOT TARGET ${_target})
-+        message(FATAL_ERROR "The first argument to qt5_use_modules must be an existing target.")
-+    endif()
-+    if ("${_link_type}" STREQUAL "LINK_PUBLIC" OR "${_link_type}" STREQUAL "LINK_PRIVATE" )
-+        set(_qt5_modules ${ARGN})
-+        set(_qt5_link_type ${_link_type})
-+    else()
-+        set(_qt5_modules ${_link_type} ${ARGN})
-+    endif()
-+
-+    if ("${_qt5_modules}" STREQUAL "")
-+        message(FATAL_ERROR "qt5_use_modules requires at least one Qt module to use.")
-+    endif()
-+    foreach(_module ${_qt5_modules})
-+        if (NOT Qt5${_module}_FOUND)
-+            find_package(Qt5${_module} PATHS "${_Qt5_COMPONENT_PATH}" NO_DEFAULT_PATH)
-+            if (NOT Qt5${_module}_FOUND)
-+                message(FATAL_ERROR "Can not use \"${_module}\" module which has not yet been found.")
-+            endif()
-+        endif()
-+        target_link_libraries(${_target} ${_qt5_link_type} ${Qt5${_module}_LIBRARIES})
-+        set_property(TARGET ${_target} APPEND PROPERTY INCLUDE_DIRECTORIES ${Qt5${_module}_INCLUDE_DIRS})
-+        set_property(TARGET ${_target} APPEND PROPERTY COMPILE_DEFINITIONS ${Qt5${_module}_COMPILE_DEFINITIONS})
-+        if (Qt5_POSITION_INDEPENDENT_CODE
-+                AND (CMAKE_VERSION VERSION_LESS 2.8.12
-+                    AND (NOT CMAKE_CXX_COMPILER_ID STREQUAL "GNU"
-+                    OR CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.0)))
-+            set_property(TARGET ${_target} PROPERTY POSITION_INDEPENDENT_CODE ${Qt5_POSITION_INDEPENDENT_CODE})
-+        endif()
-+    endforeach()
-+endfunction()
-+
- # Some wrappers for simplifying dual-Qt support
- 
- function(qt_use_modules)