diff --git a/Makefile b/Makefile
index c2c75ec87..cfdb92645 100644
--- a/Makefile
+++ b/Makefile
@@ -26,6 +26,7 @@ endif
 INC_FSGRID = -I./submodules/fsgrid/
 INC_DCCRG = -I./submodules/dccrg/
 INC_VECTORCLASS = -I ./submodules/vectorclass/ -I ./submodules/vectorclass-addon/vector3d/
+INC_EIGEN = -I ./submodules/eigen/
 
 include MAKE/Makefile.${ARCH}