diff --git a/CMakeLists.txt b/CMakeLists.txt
index f38836b..0dfa6ee 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,6 +3,8 @@
 cmake_minimum_required(VERSION 2.6)
 
 project(APRILTAGS)
+set_property(GLOBAL PROPERTY CXX_STANDARD 11)
+
 
 set(EXECUTABLE_OUTPUT_PATH ${CMAKE_BINARY_DIR})
 set(LIBRARY_OUTPUT_PATH ${CMAKE_BINARY_DIR})
diff --git a/src/Geometry.h b/src/Geometry.h
index b41dc19..029b74d 100644
--- a/src/Geometry.h
+++ b/src/Geometry.h
@@ -12,6 +12,7 @@
 // Note: Geometry.h is a bit of a misnomer, as this holds a bunch of
 // classes all used by the TagDetector class.
 
+#include <map>
 #include "AprilTypes.h"
 
 //////////////////////////////////////////////////////////////////////