diff --git a/CMakeLists.txt b/CMakeLists.txt
index ef162fd21..893bca753 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -261,11 +261,7 @@ if((CMAKE_COMPILER_IS_GNUCXX AND CMAKE_C_COMPILER_VERSION VERSION_GREATER "4.7.9
 endif()
 
 if(CMAKE_COMPILER_IS_GNUCXX)
-  if((CMAKE_C_COMPILER_VERSION VERSION_GREATER "4.8.99") OR CLANG)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c11")
-  else()
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99")
-  endif()
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c11")
 endif()
 
 # pthread_rwlock_t requires a feature flag.
diff --git a/util/generate_build_files.py b/util/generate_build_files.py
index 7341a2f3a..5ec2d6ad9 100644
--- a/util/generate_build_files.py
+++ b/util/generate_build_files.py
@@ -442,12 +442,7 @@ if(CMAKE_COMPILER_IS_GNUCXX OR CLANG)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")
   endif()
 
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fvisibility=hidden -fno-common")
-  if((CMAKE_C_COMPILER_VERSION VERSION_GREATER "4.8.99") OR CLANG)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c11")
-  else()
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99")
-  endif()
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fvisibility=hidden -fno-common -std=c11")
 endif()
 
 # pthread_rwlock_t requires a feature flag.