diff --git a/.ci_support/environment-docs.yml b/.ci_support/environment-docs.yml
index ec63c3b9..54c5b6f4 100644
--- a/.ci_support/environment-docs.yml
+++ b/.ci_support/environment-docs.yml
@@ -11,7 +11,7 @@ dependencies:
 - sphinx
 - sphinx_rtd_theme
 - cloudpickle =3.1.1
-- h5py =3.14.0
+- h5py =3.15.0
 - jupyter-book =1.0.0
 - mpi4py =4.1.1
 - python =3.12
diff --git a/.ci_support/environment-integration.yml b/.ci_support/environment-integration.yml
index a145fd70..7cb1738b 100644
--- a/.ci_support/environment-integration.yml
+++ b/.ci_support/environment-integration.yml
@@ -1,7 +1,7 @@
 channels:
 - conda-forge
 dependencies:
-- h5py =3.14.0
+- h5py =3.15.0
 - jupyter
 - mpi4py =4.1.1
 - numpy =2.3.3
diff --git a/.ci_support/environment-mpich.yml b/.ci_support/environment-mpich.yml
index 106538eb..26f9dfc7 100644
--- a/.ci_support/environment-mpich.yml
+++ b/.ci_support/environment-mpich.yml
@@ -5,7 +5,7 @@ dependencies:
 - numpy
 - mpich
 - cloudpickle =3.1.1
-- h5py =3.14.0
+- h5py =3.15.0
 - hatchling =1.27.0
 - hatch-vcs =0.5.0
 - ipython =9.0.2
diff --git a/.ci_support/environment-openmpi.yml b/.ci_support/environment-openmpi.yml
index 21c91b4d..3ebfa4f0 100644
--- a/.ci_support/environment-openmpi.yml
+++ b/.ci_support/environment-openmpi.yml
@@ -5,7 +5,7 @@ dependencies:
 - numpy
 - openmpi
 - cloudpickle =3.1.1
-- h5py =3.14.0
+- h5py =3.15.0
 - hatchling =1.27.0
 - hatch-vcs =0.5.0
 - ipython =9.0.2
diff --git a/.ci_support/environment-win.yml b/.ci_support/environment-win.yml
index ead678c6..9a217605 100644
--- a/.ci_support/environment-win.yml
+++ b/.ci_support/environment-win.yml
@@ -5,7 +5,7 @@ dependencies:
 - numpy
 - msmpi
 - cloudpickle =3.1.1
-- h5py =3.14.0
+- h5py =3.15.0
 - hatchling =1.27.0
 - hatch-vcs =0.5.0
 - ipython =9.0.2
diff --git a/binder/environment.yml b/binder/environment.yml
index 72bb4de7..ef8c3295 100644
--- a/binder/environment.yml
+++ b/binder/environment.yml
@@ -9,7 +9,7 @@ dependencies:
 - flux-pmix =0.6.0
 - hatchling =1.27.0
 - hatch-vcs =0.5.0
-- h5py =3.12.1
+- h5py =3.15.0
 - ipython =9.0.2
 - matplotlib =3.10.0
 - mpi4py =4.1.1
diff --git a/pyproject.toml b/pyproject.toml
index a9dd36fb..7008c472 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -40,7 +40,7 @@ Documentation = "https://executorlib.readthedocs.io"
 Repository = "https://github.com/pyiron/executorlib"
 
 [project.optional-dependencies]
-cache = ["h5py==3.14.0"]
+cache = ["h5py==3.15.0"]
 graph = [
     "pygraphviz==1.14",
     "networkx==3.4.2",
@@ -53,12 +53,12 @@ graphnotebook = [
 mpi = ["mpi4py==4.1.1"]
 cluster = [
     "pysqa==0.3.2",
-    "h5py==3.14.0",
+    "h5py==3.15.0",
 ]
 all = [
     "mpi4py==4.1.1",
     "pysqa==0.3.2",
-    "h5py==3.14.0",
+    "h5py==3.15.0",
     "pygraphviz==1.14",
     "networkx==3.4.2",
     "ipython==9.0.2",