diff --git a/conda/recipes/conda_build_config.yaml b/conda/recipes/conda_build_config.yaml
index 77415f3bee79..1ef8a7c224c8 100644
--- a/conda/recipes/conda_build_config.yaml
+++ b/conda/recipes/conda_build_config.yaml
@@ -36,6 +36,9 @@ doxygen:
 eigen:
   - 3.4.*
 
+hdf4:
+  - 4.2.*
+
 hdf5: # this is to move to libcurl>=8.4
   - '>1.14.0,<1.15'
 
@@ -59,8 +62,6 @@ mkl:
 muparser:
   - '>=2.3.2'
 
-nexus:
-  - 4.4.*
 # We follow conda-forge and build with the lowest supported version of numpy for forward compatibility.
 numpy:
   - 2.0.*
diff --git a/conda/recipes/mantid-developer/meta.yaml b/conda/recipes/mantid-developer/meta.yaml
index 90064ac5a843..e3a46b0ff94c 100644
--- a/conda/recipes/mantid-developer/meta.yaml
+++ b/conda/recipes/mantid-developer/meta.yaml
@@ -16,6 +16,7 @@ requirements:
     - graphviz {{ graphviz }}
     - gsl {{ gsl }}
     - h5py
+    - hdf4 {{ hdf4 }}
     - hdf5 {{ hdf5 }}
     - jemalloc {{ jemalloc }} # [linux]
     - jsoncpp {{ jsoncpp }}
@@ -27,7 +28,6 @@ requirements:
     - matplotlib {{ matplotlib }}
     - mkl {{ mkl }} # [win]
     - muparser {{ muparser }}
-    - nexus {{ nexus }}
     - ninja {{ ninja }}
     - numpy>=2.0,<2.2 # This is intentionally different to conda_build_config.yaml, will address later.
     - occt {{ occt }}
@@ -56,6 +56,7 @@ requirements:
     - texlive-core {{ texlive_core }} # [osx or linux]
     - toml {{ toml }}
     - versioningit {{ versioningit }}
+    - zlib
     - joblib
     - orsopy {{ orsopy }}
 
diff --git a/conda/recipes/mantid/meta.yaml b/conda/recipes/mantid/meta.yaml
index c3331e63036d..298903249483 100644
--- a/conda/recipes/mantid/meta.yaml
+++ b/conda/recipes/mantid/meta.yaml
@@ -34,6 +34,7 @@ requirements:
   host:
     - eigen {{ eigen }}
     - gsl {{ gsl }}
+    - hdf4 {{ hdf4 }}
     - h5py
     - hdf5 {{ hdf5 }}
     - jemalloc  {{ jemalloc }} # [osx or linux]
@@ -45,7 +46,6 @@ requirements:
     - lib3mf  # [win]
     - mkl {{ mkl }} # [win]
     - muparser {{ muparser }}
-    - nexus {{ nexus }}
     - numpy {{ numpy }}
     - occt {{ occt }}
     - python {{ python }}
@@ -54,15 +54,16 @@ requirements:
     - tbb-devel {{ tbb }}
     - pip {{ pip }}
     - versioningit {{ versioningit }}
+    - zlib
     - libglu {{ libglu }}  # [linux]
   run:
     - {{ pin_compatible("gsl", max_pin="x.x") }}
+    - {{ pin_compatible("hdf4", max_pin="x.x") }}
     - h5py
     - {{ pin_compatible("hdf5", max_pin="x.x") }}
     - jemalloc {{ jemalloc }}  # [osx or linux]
     - lib3mf  # [win]
     - mkl {{ mkl }} # [win]
-    - nexus {{ nexus }}
     - {{ pin_compatible("numpy", upper_bound="2.2") }}
     - occt {{ occt }}
     - pycifrw
@@ -76,6 +77,7 @@ requirements:
     - joblib
     - orsopy {{ orsopy }}
     - quasielasticbayes
+    - zlib
     - pydantic
 
   run_constrained: