diff --git a/codebuild/spec/buildspec_generalbatch.yml b/codebuild/spec/buildspec_generalbatch.yml
index 812b9bf4150..129d242eabb 100644
--- a/codebuild/spec/buildspec_generalbatch.yml
+++ b/codebuild/spec/buildspec_generalbatch.yml
@@ -187,6 +187,29 @@ batch:
           S2N_LIBCRYPTO: openssl-3.0
           TESTS: unit
       identifier: s2nUnitOpenssl3Gcc9
+    ### Ubuntu24 ###
+    # Openssl-1.1.1 + gcc-13: Prefer more widely used Openssl on the default
+    #   Ubuntu24 compiler.
+    # Aws-lc + clang-18: aws-lc is being built with clang; keep parity while building
+    #   s2n-tls on a newer compiler.
+    - buildspec: codebuild/spec/buildspec_ubuntu_cmake.yml
+      env:
+        compute-type: BUILD_GENERAL1_MEDIUM
+        image: 024603541914.dkr.ecr.us-west-2.amazonaws.com/docker:ubuntu24
+        privileged-mode: true
+        variables:
+          COMPILER: 'gcc-13'
+          S2N_LIBCRYPTO: 'openssl-1.1.1'
+      identifier: s2nUnitOpenssl111Gcc13
+    - buildspec: codebuild/spec/buildspec_ubuntu_cmake.yml
+      env:
+        compute-type: BUILD_GENERAL1_MEDIUM
+        image: 024603541914.dkr.ecr.us-west-2.amazonaws.com/docker:ubuntu24
+        privileged-mode: true
+        variables:
+          COMPILER: 'clang-18'
+          S2N_LIBCRYPTO: 'awslc'
+      identifier: s2nUnitAwslcClang18
     - buildspec: codebuild/spec/buildspec_amazonlinux.yml
       env:
         compute-type: BUILD_GENERAL1_LARGE
diff --git a/codebuild/spec/buildspec_ubuntu_cmake.yml b/codebuild/spec/buildspec_ubuntu_cmake.yml
new file mode 100644
index 00000000000..88360356bda
--- /dev/null
+++ b/codebuild/spec/buildspec_ubuntu_cmake.yml
@@ -0,0 +1,29 @@
+---
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You may not use
+# this file except in compliance with the License. A copy of the License is
+# located at
+#
+# http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied. See the License for the specific language governing permissions and
+# limitations under the License.
+version: 0.2
+
+phases:
+  build:
+    on-failure: ABORT
+    commands:
+      - |
+        cmake . -Bbuild \
+          -DCMAKE_C_COMPILER=/usr/bin/$COMPILER \
+          -DCMAKE_PREFIX_PATH=/usr/local/$S2N_LIBCRYPTO \
+          -DCMAKE_BUILD_TYPE=RelWithDebInfo
+      - cmake --build ./build -- -j $(nproc)
+  post_build:
+    on-failure: ABORT
+    commands:
+      - CTEST_OUTPUT_ON_FAILURE=1 CTEST_PARALLEL_LEVEL=$(nproc) make -C build test