--- CMakeLists.txt.orig	2014-11-04 18:43:47 UTC
+++ CMakeLists.txt
@@ -106,10 +106,10 @@ if(K3B_BUILD_FFMPEG_DECODER_PLUGIN)
     include(CMakePushCheckState)
     cmake_push_check_state()
 
-    if(CMAKE_COMPILER_IS_GNUCC)
+    if(CMAKE_COMPILER_IS_GNUCC OR "${CMAKE_C_COMPILER_ID}" MATCHES "Clang") 
       # FindKDE4Internal.cmake screws things up
       set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS} -std=c99)
-    endif(CMAKE_COMPILER_IS_GNUCC)
+    endif(CMAKE_COMPILER_IS_GNUCC OR "${CMAKE_C_COMPILER_ID}" MATCHES "Clang") 
 
     if(FFMPEG_INCLUDE_DIR_OLD_STYLE)
       set(CMAKE_REQUIRED_INCLUDES ${CMAKE_REQUIRED_INCLUDES} ${FFMPEG_INCLUDE_DIR_OLD_STYLE})