diff -ur sway-0.12-rc1.orig/CMakeLists.txt sway-0.12-rc1/CMakeLists.txt
--- sway-0.12-rc1.orig/CMakeLists.txt	2017-02-25 18:12:20.863466778 +0000
+++ sway-0.12-rc1/CMakeLists.txt	2017-02-25 23:08:13.393160932 +0000
@@ -14,6 +14,11 @@
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wextra")
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-parameter")
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror")
+if (CMAKE_COMPILER_IS_GNUCC)
+    if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 7.0)
+        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wimplicit-fallthrough=0")
+    endif()
+endif()
 
 list(INSERT CMAKE_MODULE_PATH 0
 	${CMAKE_CURRENT_SOURCE_DIR}/CMake