diff --git a/.pipelines/ci.yml b/.pipelines/ci.yml
index 20e36ea61..d7e260a06 100644
--- a/.pipelines/ci.yml
+++ b/.pipelines/ci.yml
@@ -379,7 +379,7 @@ stages:
 
     - script: |
         call $(vsdevcmd)
-        call .\build.bat -DOCOS_ENABLE_CTEST=ON -DOCOS_ONNXRUNTIME_VERSION="$(ort.version)" -DONNXRUNTIME_PKG_DIR=.\onnxruntime-win-x64-$(ort.version)
+        call .\build.bat -DOCOS_ENABLE_CTEST=ON -DOCOS_ONNXRUNTIME_VERSION="$(ort.version)" -DONNXRUNTIME_PKG_DIR=.\onnxruntime-win-x64-$(ort.version) -DOCOS_ENABLE_C_API=ON
       displayName: build the customop library with onnxruntime
 
     - script: |
@@ -536,7 +536,7 @@ stages:
           call .\build.bat -T cuda="%CUDA_PATH%" -DOCOS_ENABLE_CTEST=ON^
             -DCMAKE_CUDA_FLAGS_INIT=-allow-unsupported-compiler^
             -DOCOS_USE_CUDA=ON -DCMAKE_CUDA_ARCHITECTURES=70;86^
-            -DOCOS_ONNXRUNTIME_VERSION="$(ORT_VERSION)" -DONNXRUNTIME_PKG_DIR=.\onnxruntime-win-x64-gpu-$(ORT_VERSION)
+            -DOCOS_ONNXRUNTIME_VERSION="$(ORT_VERSION)" -DONNXRUNTIME_PKG_DIR=.\onnxruntime-win-x64-gpu-$(ORT_VERSION) -DOCOS_ENABLE_C_API=ON
         displayName: build the customop library with onnxruntime
 
       - script: |
diff --git a/.pipelines/templates/build-package-for-windows.yml b/.pipelines/templates/build-package-for-windows.yml
index 3fe6d86fe..99f962979 100644
--- a/.pipelines/templates/build-package-for-windows.yml
+++ b/.pipelines/templates/build-package-for-windows.yml
@@ -49,7 +49,7 @@ jobs:
         displayName: 'build onnxruntime-extensions and run tests'
         inputs:
           filename: '.\build_lib.bat'
-          arguments: '--${{parameters.BuildPlatform}} --build_dir $(Build.BinariesDirectory)/out --config RelWithDebInfo --cmake_generator "Visual Studio 17 2022" --enable_cxx_tests ${{parameters.AdditionalBuildFlags}}'
+          arguments: '--${{parameters.BuildPlatform}} --build_dir $(Build.BinariesDirectory)/out --config RelWithDebInfo --cmake_generator "Visual Studio 17 2022" --enable_cxx_tests ${{parameters.AdditionalBuildFlags}} --cmake_extra_defines OCOS_ENABLE_C_API=ON'
           modifyEnvironment: true
           workingFolder: $(Build.SourcesDirectory)
     - ${{ else }}:
@@ -57,7 +57,7 @@ jobs:
         displayName: 'build onnxruntime-extensions'
         inputs:
           filename: '.\build_lib.bat'
-          arguments: '--${{parameters.BuildPlatform}} --build_dir $(Build.BinariesDirectory)/out --config RelWithDebInfo --cmake_generator "Visual Studio 17 2022" ${{parameters.AdditionalBuildFlags}}'
+          arguments: '--${{parameters.BuildPlatform}} --build_dir $(Build.BinariesDirectory)/out --config RelWithDebInfo --cmake_generator "Visual Studio 17 2022" ${{parameters.AdditionalBuildFlags}} --cmake_extra_defines OCOS_ENABLE_C_API=ON'
           modifyEnvironment: true
           workingFolder: $(Build.SourcesDirectory)
 
diff --git a/tools/ci_build/github/azure-pipeline/templates/build-package-for-windows.yml b/tools/ci_build/github/azure-pipeline/templates/build-package-for-windows.yml
index e802d64d6..50d9ab7fc 100644
--- a/tools/ci_build/github/azure-pipeline/templates/build-package-for-windows.yml
+++ b/tools/ci_build/github/azure-pipeline/templates/build-package-for-windows.yml
@@ -56,7 +56,7 @@ jobs:
         displayName: 'build onnxruntime-extensions and run tests'
         inputs:
           filename: '.\build_lib.bat'
-          arguments: '--${{parameters.BuildPlatform}} --build_dir $(Build.BinariesDirectory)/out --config RelWithDebInfo --cmake_generator "Visual Studio 17 2022" --enable_cxx_tests ${{parameters.AdditionalBuildFlags}}'
+          arguments: '--${{parameters.BuildPlatform}} --build_dir $(Build.BinariesDirectory)/out --config RelWithDebInfo --cmake_generator "Visual Studio 17 2022" --enable_cxx_tests ${{parameters.AdditionalBuildFlags}} --cmake_extra_defines OCOS_ENABLE_C_API=ON'
           modifyEnvironment: true
           workingFolder: $(Build.SourcesDirectory)
     - ${{ else }}:
@@ -64,7 +64,7 @@ jobs:
         displayName: 'build onnxruntime-extensions'
         inputs:
           filename: '.\build_lib.bat'
-          arguments: '--${{parameters.BuildPlatform}} --build_dir $(Build.BinariesDirectory)/out --config RelWithDebInfo --cmake_generator "Visual Studio 17 2022" ${{parameters.AdditionalBuildFlags}}'
+          arguments: '--${{parameters.BuildPlatform}} --build_dir $(Build.BinariesDirectory)/out --config RelWithDebInfo --cmake_generator "Visual Studio 17 2022" ${{parameters.AdditionalBuildFlags}} --cmake_extra_defines OCOS_ENABLE_C_API=ON'
           modifyEnvironment: true
           workingFolder: $(Build.SourcesDirectory)
 
diff --git a/version.txt b/version.txt
index e815b861f..4312e0d0c 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-0.15.1
+0.15.2