diff --git a/.pfnci/build_submit.sh b/.pfnci/build_submit.sh
index c4876a8..db20bd5 100755
--- a/.pfnci/build_submit.sh
+++ b/.pfnci/build_submit.sh
@@ -30,7 +30,7 @@ submit_job() {
 
 # wheels (Windows)
 for CUDA in 12.x 13.x; do
-  for PYTHON in 3.10 3.11 3.12 3.13 3.14; do  # TODO add 3.14t
+  for PYTHON in 3.10 3.11 3.12 3.13 3.14 3.14t; do
     submit_job cupy-wheel-win ".pfnci\\wheel-windows\\main.bat ${CUDA} ${PYTHON} ${BRANCH} ${JOB_GROUP}"
   done
 done
diff --git a/.pfnci/config.pbtxt b/.pfnci/config.pbtxt
index 31d168e..eb47997 100644
--- a/.pfnci/config.pbtxt
+++ b/.pfnci/config.pbtxt
@@ -41,7 +41,7 @@ configs {
     time_limit {
       seconds: 10800
     }
-    command: ".pfnci\\wheel-windows\\main.bat 13.x 3.14"
+    command: ".pfnci\\wheel-windows\\main.bat 13.x 3.14t"
   }
 }
 configs {
diff --git a/.pfnci/wheel-windows/_flexci.ps1 b/.pfnci/wheel-windows/_flexci.ps1
index f577a67..5a91561 100644
--- a/.pfnci/wheel-windows/_flexci.ps1
+++ b/.pfnci/wheel-windows/_flexci.ps1
@@ -1,4 +1,5 @@
 function ActivatePython($version) {
+    $pyexe = "python.exe"
     if ($version -eq "3.9") {
         $pydir = "Python39"
     } elseif ($version -eq "3.10") {
@@ -11,10 +12,14 @@ function ActivatePython($version) {
         $pydir = "Python313"
     } elseif ($version -eq "3.14") {
         $pydir = "Python314"
+    } elseif ($version -eq "3.14t") {
+        $pydir = "Python314"
+        $pyexe = "python3.14t.exe"
     } else {
         throw "Unsupported Python version: $version"
     }
     $Env:PATH = "C:\Development\Python\$pydir;C:\Development\Python\$pydir\Scripts;" + $Env:PATH
+    return "C:\Development\Python\$pydir\$pyexe"
 }
 
 function ActivateCUDA($version) {
diff --git a/.pfnci/wheel-windows/build.ps1 b/.pfnci/wheel-windows/build.ps1
index b1332ca..6b9c1f7 100644
--- a/.pfnci/wheel-windows/build.ps1
+++ b/.pfnci/wheel-windows/build.ps1
@@ -30,14 +30,14 @@ function UninstallCuTENSOR($cuda_path) {
 # Activate target CUDA/Python
 ActivateCUDA $cuda
 $cuda_path = $Env:CUDA_PATH
-ActivatePython $python
+$python_exe = ActivatePython $python
 
 # Show build configuration
 echo ">> Environment Variables"
 echo "     CUDA_PATH:   $cuda_path"
 echo "     PATH:        $Env:PATH"
 echo ">> Python Version:"
-RunOrDie python -V
+RunOrDie $python_exe -V
 
 # Clone CuPy and checkout the target branch
 if ($Env:CUPY_RELEASE_NO_CLONE -eq "1") {
@@ -57,20 +57,20 @@ if ($Env:CUPY_RELEASE_NO_CLONE -eq "1") {
 
 # Install dependencies
 echo ">> Updating packaging utilities..."
-RunOrDie python -m pip install -U setuptools pip
+RunOrDie $python_exe -m pip install -U setuptools pip
 echo ">> Installing dependences for wheel build..."
-RunOrDie python -m pip install -U -r ./requirements.txt -r ./builder/requirements.cupy-build.txt wheel pytest
+RunOrDie $python_exe -m pip install -U -r ./requirements.txt -r ./builder/requirements.cupy-build.txt wheel pytest
 echo ">> Packages installed:"
-RunOrDie python -m pip list
+RunOrDie $python_exe -m pip list
 
 # Build
 # Note: cuTENSOR will be installed by the tool.
 echo ">> Starting build..."
-RunOrDie python ./dist.py --action build --target wheel-win --source cupy --python $python --cuda $cuda
+RunOrDie $python_exe ./dist.py --action build --target wheel-win --source cupy --python $python --cuda $cuda
 
 # Get wheel name
 $dist_config = @(
-    python .\get_dist_info.py --target wheel-win --source cupy --python $python --cuda $cuda `
+    & $python_exe .\get_dist_info.py --target wheel-win --source cupy --python $python --cuda $cuda `
     | ConvertFrom-Csv -Delimiter "=" -Header "Key", "Value"
 )
 $wheel_file = $dist_config[0].Value
@@ -84,13 +84,13 @@ UninstallCuTENSOR $cuda_path
 
 # Verify
 echo ">> Validating with twine check..."
-RunOrDie python -m twine check --strict $wheel_file
+RunOrDie $python_exe -m twine check --strict $wheel_file
 echo ">> Starting verification..."
-RunOrDie python ./dist.py --action verify --target wheel-win --python $python --cuda $cuda --dist $wheel_file --test release-tests/common --test release-tests/pkg_wheel
+RunOrDie $python_exe ./dist.py --action verify --target wheel-win --python $python --cuda $cuda --dist $wheel_file --test release-tests/common --test release-tests/pkg_wheel
 
 # Show build configuration in CuPy
 echo ">> Build configuration"
-RunOrDie python -c "import cupy; cupy.show_config()"
+RunOrDie $python_exe -c "import cupy; cupy.show_config()"
 
 # Upload to GCS
 if ($job_group -eq "") {
diff --git a/builder/agent.py b/builder/agent.py
index 732a87c..3e3f78e 100755
--- a/builder/agent.py
+++ b/builder/agent.py
@@ -71,7 +71,7 @@ def main(self) -> None:
         env: dict[str, str] = {}
 
         for kv in args.env:
-            pair = kv.split('=', 2)
+            pair = kv.split('=', 1)
             assert len(pair) == 2, 'invalid --env format'
             env[pair[0]] = pair[1]