diff --git a/eic-spack.sh b/eic-spack.sh
index 65e94772ccb5b028a6862dd6703a4fea1ad6ac3b..911ce41b594cc663a581e9b63f6c146b019986b7 100644
--- a/eic-spack.sh
+++ b/eic-spack.sh
@@ -3,4 +3,4 @@ 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="6aed060d869e3ff825994354226243921a211261"
+EICSPACK_VERSION="dbb544200a6e2b347e732965a6cc6d78f3fb71cc"
diff --git a/spack-environment/packages.yaml b/spack-environment/packages.yaml
index 2ef546645fd80de2d23ddc5c4fe96d09874b6be7..1dcb8bdb3295b2e95f0edea3231c9f5285c10fd9 100644
--- a/spack-environment/packages.yaml
+++ b/spack-environment/packages.yaml
@@ -170,6 +170,9 @@ packages:
     require:
     - '@3.3.0'
     - +python +rootio
+  hepmcmerger:
+    require:
+    - '@1.0.4'
   heppdt:
     require:
     - '@2.06.01'
diff --git a/spack-environment/xl/spack.yaml b/spack-environment/xl/spack.yaml
index 92bfd11a5e9e867ce1acd1839e387ce62a422fda..a62ef016c70c8e02621562f019c4ecf9c7e67683 100644
--- a/spack-environment/xl/spack.yaml
+++ b/spack-environment/xl/spack.yaml
@@ -41,6 +41,7 @@ spack:
   - gfal2
   - graphviz
   - hepmc3
+  - hepmcmerger
   - heppdt
   - imagemagick
   - irt