diff --git a/Eigen/src/Core/StableNorm.h b/Eigen/src/Core/StableNorm.h
index 10cd55157..04fe0b371 100644
--- a/Eigen/src/Core/StableNorm.h
+++ b/Eigen/src/Core/StableNorm.h
@@ -10,10 +10,6 @@
 #ifndef EIGEN_STABLENORM_H
 #define EIGEN_STABLENORM_H
 
-#if EIGEN_HAS_CXX11_ATOMIC
-#include <atomic>
-#endif
-
 namespace Eigen { 
 
 namespace internal {