diff --git a/spack.yaml b/spack.yaml
index a3954036bae1aebb58b0b0e74d67c68db909705b..104f112a219a782e14d50c8417ad55a88e1960fb 100644
--- a/spack.yaml
+++ b/spack.yaml
@@ -25,7 +25,7 @@ spack:
     - podio@0.13.1
     - geant4@10.7.1 cxxstd=17 +opengl +vecgeom +x11 +qt +threads ^qt +opengl
     - dd4hep@1.17p1 +geant4 +assimp +hepmc3 +ipo +lcio
-    - acts@8.03.0p1 +dd4hep +digitization +identification +json +tgeo +ipo +examples +fatras
+    - acts@8.03.0p1 +dd4hep +digitization +identification +json +tgeo +ipo +examples +fatras +geant4
     - genfit@2.00.00
     - gaudi@36.0
     - dawn@3_91a