diff --git a/pyproject.toml b/pyproject.toml
index 4e29bc1..5be9c61 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools>=61.0"]
+requires = ["setuptools>=61.0", "setuptools-git-versioning"]
 build-backend = "setuptools.build_meta"
 
 # Self-descriptive entries which should always be present
diff --git a/quax/integrals/makefile b/quax/integrals/makefile
index ce46153..8b8bf9f 100644
--- a/quax/integrals/makefile
+++ b/quax/integrals/makefile
@@ -13,7 +13,7 @@ I1 := $(LIBINT_PREFIX)/include
 I2 := $(LIBINT_PREFIX)/include/libint2
 L1 := $(LIBINT_PREFIX)/lib
 # Eigen headers location 
-I3 := $(CONDA_PREFIX)/eigen3
+I3 := $(CONDA_PREFIX)/include/eigen3
 # HDF5 headers, static and shared libraries 
 I6 := $(CONDA_PREFIX)/include
 L2 := $(CONDA_PREFIX)/lib