diff --git a/.github/workflows/test_nwx_library.yaml b/.github/workflows/test_nwx_library.yaml
index 9c43626..1204ac2 100644
--- a/.github/workflows/test_nwx_library.yaml
+++ b/.github/workflows/test_nwx_library.yaml
@@ -23,7 +23,7 @@ on:
         description: "String of a JSON list of compilers to test"
         type: string
         required: false
-        default: '["gcc-11", "clang-14"]'
+        default: '["gcc-14", "clang-18"]'
       repo_toolchain:
         description: "Path (from repo root) to a CMake toolchain for repo specific settings"
         type: string
diff --git a/nwx_build_environment/add_gauxc.dockerfile b/nwx_build_environment/add_gauxc.dockerfile
index c0796bc..4421e02 100644
--- a/nwx_build_environment/add_gauxc.dockerfile
+++ b/nwx_build_environment/add_gauxc.dockerfile
@@ -24,7 +24,6 @@ RUN cd /tmp \
     && git checkout ${VERSION} \
     && cmake -Bbuild -H. -GNinja \
     -DGAUXC_ENABLE_HDF5=OFF \
-    -DGAUXC_ENABLE_OPENMP=OFF \
     -DBUILD_TESTING=OFF \
     -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
     -DCMAKE_INSTALL_PREFIX=/nwx_dependencies/${COMPILER} \
diff --git a/nwx_build_environment/buildenv.sh b/nwx_build_environment/buildenv.sh
index 58ca867..a0ea6c1 100755
--- a/nwx_build_environment/buildenv.sh
+++ b/nwx_build_environment/buildenv.sh
@@ -19,7 +19,7 @@ deps=("cereal" "gauxc" "libfort" "spdlog" "libint")
 for dep in "${deps[@]}"
 do
     docker build -t nwx_buildenv -f add_${dep}.dockerfile --build-arg COMPILER=gcc-14 .
-    docker build -t nwx_buildenv -f add_${dep}.dockerfile --build-arg COMPILER=clang-19 .
+    docker build -t nwx_buildenv -f add_${dep}.dockerfile --build-arg COMPILER=clang-18 .
     docker image prune -f
 done
 
diff --git a/nwx_build_environment/nwx_buildenv.dockerfile b/nwx_build_environment/nwx_buildenv.dockerfile
index 1df2428..37ee3c7 100644
--- a/nwx_build_environment/nwx_buildenv.dockerfile
+++ b/nwx_build_environment/nwx_buildenv.dockerfile
@@ -17,7 +17,7 @@ FROM ubuntu:noble
 RUN apt-get update \
     && DEBIAN_FRONTEND=noninteractive TZ=Etc/UTC apt-get install -y \
     gcc-14 g++-14 \
-    clang-19 libc++-19-dev libc++abi-19-dev \
+    clang-18 libc++-18-dev libc++abi-18-dev \
     libomp-dev \
     doxygen \
     graphviz \
diff --git a/nwx_build_environment/toolchains/clang-19.cmake b/nwx_build_environment/toolchains/clang-18.cmake
similarity index 91%
rename from nwx_build_environment/toolchains/clang-19.cmake
rename to nwx_build_environment/toolchains/clang-18.cmake
index 7962416..0eaaa4a 100644
--- a/nwx_build_environment/toolchains/clang-19.cmake
+++ b/nwx_build_environment/toolchains/clang-18.cmake
@@ -12,8 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-set(CMAKE_C_COMPILER clang-19)
-set(CMAKE_CXX_COMPILER clang++-19)
+set(CMAKE_C_COMPILER clang-18)
+set(CMAKE_CXX_COMPILER clang++-18)
 
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")
 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -stdlib=libc++ -lc++abi")
diff --git a/nwx_build_environment/toolchains/nwx_clang-19.cmake b/nwx_build_environment/toolchains/nwx_clang-18.cmake
similarity index 94%
rename from nwx_build_environment/toolchains/nwx_clang-19.cmake
rename to nwx_build_environment/toolchains/nwx_clang-18.cmake
index 1c2c6f2..ede2d7a 100644
--- a/nwx_build_environment/toolchains/nwx_clang-19.cmake
+++ b/nwx_build_environment/toolchains/nwx_clang-18.cmake
@@ -12,5 +12,5 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-include(/toolchains/clang-19.cmake)
+include(/toolchains/clang-18.cmake)
 include(/toolchains/nwx_base.cmake)