diff --git a/spack-environment/packages.yaml b/spack-environment/packages.yaml
index 64342f380a3e270b112b7e893cda6f4c76f9d427..0d91a1d216b25921d3ca8cb4af2bda23256e1b2d 100644
--- a/spack-environment/packages.yaml
+++ b/spack-environment/packages.yaml
@@ -156,7 +156,7 @@ packages:
     - +expat +pangocairo
   hepmc3:
     require:
-    - '@3.2.7'
+    - '@3.3.0'
     - +python +rootio
   heppdt:
     require:
diff --git a/spack.sh b/spack.sh
index 3abea7e4f059732cece327dd98481c2205b8dbbc..c55cee5499aef3b228a0b5a010750a1d43b9e0b7 100644
--- a/spack.sh
+++ b/spack.sh
@@ -22,6 +22,8 @@ b894acf1fca8eb5cc52d2267b0c4c187065998c0
 8b45fa089e24c6ab7de2eaf614977369e69daa54
 2d8ca8af6932dfd50204d1e4f6fe587dec7beef5
 d3bf1e04fca844abb7c1eeac38dda4e126c81b67
+81125c3bd80e71a2e57c7fcff8e02c4b3add5b90
+8b2fec61f23a7b8230c0ed0378d90d04d8f590d8
 ---
 ## Optional hash table with comma-separated file list
 read -r -d '' SPACK_CHERRYPICKS_FILES <<- \
@@ -43,3 +45,5 @@ read -r -d '' SPACK_CHERRYPICKS_FILES <<- \
 ## 8b45fa089e24c6ab7de2eaf614977369e69daa54: geant4: support Qt5 and Qt6
 ## 2d8ca8af6932dfd50204d1e4f6fe587dec7beef5: qt-*: add v6.7.1, v6.7.2
 ## d3bf1e04fca844abb7c1eeac38dda4e126c81b67: py-vector: add through v1.4.1 (switch to hatchling)
+## 81125c3bd80e71a2e57c7fcff8e02c4b3add5b90: hepmc3: pass root variant cxxstd as HEPMC3_CXX_STANDARD
+## 8b2fec61f23a7b8230c0ed0378d90d04d8f590d8: hepmc3: add v3.3.0