diff --git a/.github/workflows/XmsInterp-CI.yaml b/.github/workflows/XmsInterp-CI.yaml
index 522f7660..b20f1c2e 100644
--- a/.github/workflows/XmsInterp-CI.yaml
+++ b/.github/workflows/XmsInterp-CI.yaml
@@ -183,7 +183,7 @@ jobs:
       CONAN_BUILD_TYPES: ${{ matrix.build_type }}
       CONAN_GCC_VERSIONS: ${{ matrix.compiler-version }}
       CONAN_DOCKER_IMAGE: docker.aquaveo.com/aquaveo/conan-docker/conan-gcc${{ matrix.compiler-version }}-py${{ matrix.python-version }}:latest
-      CONAN_PIP_INSTALL: 'conan-package-tools==0.35.1'
+      CONAN_PIP_INSTALL: 'conan-package-tools==0.35.1 numpy==1.26.4'
       CONAN_PIP_PACKAGE: 'conan==1.41.0'
       # Aquapi Variables
       AQUAPI_USERNAME: ${{ secrets.AQUAPI_USERNAME_SECRET }}
diff --git a/_package/setup.py b/_package/setup.py
index a47523b7..1c1ffb1e 100644
--- a/_package/setup.py
+++ b/_package/setup.py
@@ -10,7 +10,7 @@
 os.chdir(os.path.normpath(os.path.join(os.path.abspath(__file__), os.pardir)))
 
 requires = [
-    'numpy',
+    'numpy<2.0.0',
     'xmscore>=6.0.0',
     'xmsgrid>=7.0.0, <8.0.0',
 ]