diff --git a/6d8f7d303e.patch b/6d8f7d303e.patch
new file mode 100644
index 0000000..2620ab8
--- /dev/null
+++ b/6d8f7d303e.patch
@@ -0,0 +1,75 @@
+From 6d8f7d303ec319539add2f0ba5331c2dab9d23c7 Mon Sep 17 00:00:00 2001
+From: Milan Crha <mcrha@redhat.com>
+Date: Wed, 14 Apr 2021 16:58:08 +0200
+Subject: [PATCH] PrintableOptions.cmake: Correct variable name comparison
+
+CMake 3.20.1 errors out with:
+
+CMake Error at cmake/modules/PrintableOptions.cmake:38 (message):
+   variable name cannot be empty
+ Call Stack (most recent call first):
+   CMakeLists.txt:152 (add_printable_variable)
+
+Change how the parameter value is compared, to fix it.
+---
+ cmake/modules/PrintableOptions.cmake | 20 ++++++++++----------
+ 1 file changed, 10 insertions(+), 10 deletions(-)
+
+diff --git a/cmake/modules/PrintableOptions.cmake b/cmake/modules/PrintableOptions.cmake
+index ba1c9d0b..339f1da4 100644
+--- a/cmake/modules/PrintableOptions.cmake
++++ b/cmake/modules/PrintableOptions.cmake
+@@ -19,40 +19,40 @@
+ #    prints all the build options previously added with the above functions
+ 
+ macro(add_printable_variable_bare _name)
+-	if(_name STREQUAL "")
++	if("${_name}" STREQUAL "")
+ 		message(FATAL_ERROR "variable name cannot be empty")
+-	endif(_name STREQUAL "")
++	endif("${_name}" STREQUAL "")
+ 	list(APPEND _printable_options ${_name})
+ endmacro()
+ 
+ macro(add_printable_option _name _description _default_value)
+-	if(_name STREQUAL "")
++	if("${_name}" STREQUAL "")
+ 		message(FATAL_ERROR "option name cannot be empty")
+-	endif(_name STREQUAL "")
++	endif("${_name}" STREQUAL "")
+ 	option(${_name} ${_description} ${_default_value})
+ 	add_printable_variable_bare(${_name})
+ endmacro()
+ 
+ macro(add_printable_variable _name _description _default_value)
+-	if(_name STREQUAL "")
++	if("${_name}" STREQUAL "")
+ 		message(FATAL_ERROR "variable name cannot be empty")
+-	endif(_name STREQUAL "")
++	endif("${_name}" STREQUAL "")
+ 	set(${_name} ${_default_value} CACHE STRING ${_description})
+ 	add_printable_variable_bare(${_name})
+ endmacro()
+ 
+ macro(add_printable_variable_path _name _description _default_value)
+-	if(_name STREQUAL "")
++	if("${_name}" STREQUAL "")
+ 		message(FATAL_ERROR "path variable name cannot be empty")
+-	endif(_name STREQUAL "")
++	endif("${_name}" STREQUAL "")
+ 	set(${_name} ${_default_value} CACHE PATH ${_description})
+ 	add_printable_variable_bare(${_name})
+ endmacro()
+ 
+ macro(add_printable_variable_filepath _name _description _default_value)
+-	if(_name STREQUAL "")
++	if("${_name}" STREQUAL "")
+ 		message(FATAL_ERROR "filepath variable name cannot be empty")
+-	endif(_name STREQUAL "")
++	endif("${_name}" STREQUAL "")
+ 	set(${_name} ${_default_value} CACHE FILEPATH ${_description})
+ 	add_printable_variable_bare(${_name})
+ endmacro()
+-- 
+GitLab
+
diff --git a/evolution-ews.changes b/evolution-ews.changes
index cf5286d..88f86d7 100644
--- a/evolution-ews.changes
+++ b/evolution-ews.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Fri Apr 30 07:46:05 UTC 2021 - Dominique Leuenberger <dimstar@opensuse.org>
+
+- Add 6d8f7d303e.patch: Fix build with cmake 3.20.1.
+
 -------------------------------------------------------------------
 Sat Mar 20 08:27:18 UTC 2021 - Michael Gorse <mgorse@suse.com>
 
diff --git a/evolution-ews.spec b/evolution-ews.spec
index b6f0169..30fd231 100644
--- a/evolution-ews.spec
+++ b/evolution-ews.spec
@@ -27,6 +27,8 @@ License:        LGPL-2.1-only
 Group:          Productivity/Networking/Email/Clients
 URL:            https://wiki.gnome.org/Apps/Evolution
 Source0:        https://download.gnome.org/sources/evolution-ews/3.40/%{name}-%{version}.tar.xz
+# PATCH-FIX-UPSTREAM 6d8f7d303e.patch dimstar@opensuse.org -- Fix build with cmake 3.20.1
+Patch0:         https://gitlab.gnome.org/GNOME/evolution-ews/-/commit/6d8f7d303e.patch
 
 BuildRequires:  c++_compiler
 BuildRequires:  cmake