diff -up kservice-5.36.0/CMakeLists.txt.flex kservice-5.36.0/CMakeLists.txt
--- kservice-5.36.0/CMakeLists.txt.flex	2017-07-02 03:10:31.000000000 -0500
+++ kservice-5.36.0/CMakeLists.txt	2017-07-03 14:06:30.065476955 -0500
@@ -64,6 +64,8 @@ set_package_properties(BISON PROPERTIES
     PURPOSE "Required for the Trader parser"
 )
 
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99")
+
 add_definitions(-DTRANSLATION_DOMAIN=\"kservice5\")
 if (IS_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/po")
     ki18n_install(po)