diff --git a/cmake/modules/FindFlann.cmake b/cmake/modules/FindFlann.cmake
deleted file mode 100644
index 98674d230..000000000
--- a/cmake/modules/FindFlann.cmake
+++ /dev/null
@@ -1,28 +0,0 @@
-###############################################################################
-# Find Flann
-#
-# This sets the following variables:
-# FLANN_FOUND - True if FLANN was found.
-# FLANN_INCLUDE_DIRS - Directories containing the FLANN include files.
-# FLANN_LIBRARIES - Libraries needed to use FLANN.
-# FLANN_DEFINITIONS - Compiler flags for FLANN.
-
-find_package(PkgConfig)
-pkg_check_modules(PC_FLANN flann)
-set(FLANN_DEFINITIONS ${PC_FLANN_CFLAGS_OTHER})
-
-find_path(FLANN_INCLUDE_DIR flann/flann.hpp
-    HINTS ${PC_FLANN_INCLUDEDIR} ${PC_FLANN_INCLUDE_DIRS})
-
-find_library(FLANN_LIBRARY flann_cpp
-    HINTS ${PC_FLANN_LIBDIR} ${PC_FLANN_LIBRARY_DIRS})
-
-set(FLANN_INCLUDE_DIRS ${FLANN_INCLUDE_DIR})
-set(FLANN_LIBRARIES ${FLANN_LIBRARY})
-
-include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(Flann DEFAULT_MSG
-    FLANN_LIBRARY FLANN_INCLUDE_DIR)
-
-mark_as_advanced(FLANN_LIBRARY FLANN_INCLUDE_DIR)
-
diff --git a/xs/CMakeLists.txt b/xs/CMakeLists.txt
index 69e03779a..7fd81f610 100644
--- a/xs/CMakeLists.txt
+++ b/xs/CMakeLists.txt
@@ -2,10 +2,6 @@
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
-# Enable C11 language standard.
-set(CMAKE_C_STANDARD 11)
-set(CMAKE_C_STANDARD_REQUIRED ON)
-
 # Add our own cmake module path.
 list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/modules/)