diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index cfaed873ce..4a321f00e7 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -40,7 +40,7 @@ jobs:
           environment-file: ci/environment.yml
           create-args: >-
             python=${{ matrix.python-version }}
-            cmake=3.21.1
+            cmake=3.30.0
 
       - name: Install Windows Conda Packages
         if: contains(matrix.os, 'windows')
@@ -454,12 +454,12 @@ jobs:
           create-args: >-
             llvmdev=11.1.0
             bison=3.4
-            re2c
-            zlib
-            cmake
-            make
+            re2c=2.2
+            zlib=1.3.1
+            cmake=3.30.0
+            make=4.3
             python=${{ matrix.python-version }}
-            numpy
+            numpy=1.26.4
 
       - uses: hendrikmuhs/ccache-action@main
         with:
@@ -508,12 +508,9 @@ jobs:
         with:
           environment-file: ci/environment.yml
           create-args: >-
-            jupyter
-            nlohmann_json
+            jupyter=1.0.0
             python=3.10
             bison=3.4
-            xeus=5.1.0
-            xeus-zmq=3.0.0
 
       - uses: hendrikmuhs/ccache-action@main
         with:
diff --git a/ci/environment.yml b/ci/environment.yml
index 55b82c68c3..db5ded2261 100644
--- a/ci/environment.yml
+++ b/ci/environment.yml
@@ -13,9 +13,9 @@ dependencies:
   - jupyter_kernel_test=0.4.4
   - xonsh=0.13.3
   - re2c=2.2
-  - numpy=1.23.4
-  - zlib
-  - zstd
+  - numpy=1.26.4
+  - zlib=1.3.1
+  - zstd=1.5.6
   - ninja=1.11.0
   - rapidjson=1.1.0
 #  - bison=3.4  [not win]