diff --git a/eic-spack.sh b/eic-spack.sh
index 59a01581..acdf0327 100644
--- a/eic-spack.sh
+++ b/eic-spack.sh
@@ -5,4 +5,4 @@ EICSPACK_ORGREPO="eic/eic-spack"
 
 ## EIC spack commit hash or github version, e.g. v0.19.7
 ## note: nightly builds could use a branch e.g. releases/v0.19
-EICSPACK_VERSION="8d090a161331ff5e286ee094eb65adfa35aa6225"
+EICSPACK_VERSION="a4a400df716c92e034e564e2427626a430eb06cb"
diff --git a/spack-environment/packages.yaml b/spack-environment/packages.yaml
index 3a1a25ef..06fe5a46 100644
--- a/spack-environment/packages.yaml
+++ b/spack-environment/packages.yaml
@@ -126,7 +126,7 @@ packages:
   dd4hep:
     require:
     - '@1.36'
-    - +ddg4 +ddcad +edm4hep +hepmc3 +xercesc
+    - +ddg4 +ddcad +edm4hep +g4hepem +hepmc3 +xercesc
     - any_of: [+ddeve +utilityapps, -ddeve -utilityapps] # FIXME ^root +x +opengl when +utilityapps
   doxygen:
     require:
@@ -329,7 +329,7 @@ packages:
     - '@0.0.3'
   npsim:
     require:
-    - '@1.6.1'
+    - '@git.g4hepem'
     - +http
     - any_of: [+geocad, -geocad]
   ollama: