diff --git a/windows-release/msi-steps.yml b/windows-release/msi-steps.yml
index ce01ca13..fb096c79 100644
--- a/windows-release/msi-steps.yml
+++ b/windows-release/msi-steps.yml
@@ -67,6 +67,10 @@ steps:
         Include: ''
         ExportCommand: SignCommand
         SigningCertificate: ${{ parameters.SigningCertificate }}
+        # WiX is struggling with WIF authentication and sign.exe right now,
+        # so we still rely on the client secret for legacy builds.
+        # We disable the service connection here to skip the login steps.
+        AzureServiceConnectionName: ''
 
     - powershell: |
         $cmd = $env:SignCommand -replace '"', '\"'
@@ -81,12 +85,12 @@ steps:
     displayName: 'Build launcher installer'
     env:
       Platform: x86
+      # Only need the variable here for msi.props to detect
+      SigningCertificate: ${{ parameters.SigningCertificate }}
       ${{ if parameters.SigningCertificate }}:
         AZURE_TENANT_ID: $(TrustedSigningTenantId)
         AZURE_CLIENT_ID: $(TrustedSigningClientId)
-        AZURE_CLIENT_SECRET: $(TrustedSigningSecret)
-        # Only need the variable here for msi.props to detect
-        SigningCertificate: ${{ parameters.SigningCertificate }}
+        AZURE_CLIENT_SECRET: $(TrustedSigningClientSecret)
 
   - ${{ each b in parameters.Bundles }}:
     - script: |
@@ -99,12 +103,12 @@ steps:
         PYTHONHOME: $(Build.SourcesDirectory)
         ${{ if b.TclTkArtifact }}:
           TclTkLibraryDir: $(Pipeline.Workspace)\${{ b.TclTkArtifact }}
+        # Only need the variable here for msi.props to detect
+        SigningCertificate: ${{ parameters.SigningCertificate }}
         ${{ if parameters.SigningCertificate }}:
           AZURE_TENANT_ID: $(TrustedSigningTenantId)
           AZURE_CLIENT_ID: $(TrustedSigningClientId)
-          AZURE_CLIENT_SECRET: $(TrustedSigningSecret)
-          # Only need the variable here for msi.props to detect
-          SigningCertificate: ${{ parameters.SigningCertificate }}
+          AZURE_CLIENT_SECRET: $(TrustedSigningClientSecret)
 
   - powershell: |
       del $env:ResponseFile -ErrorAction Continue
diff --git a/windows-release/sign-files.yml b/windows-release/sign-files.yml
index 127a2e07..6809d9c9 100644
--- a/windows-release/sign-files.yml
+++ b/windows-release/sign-files.yml
@@ -7,10 +7,12 @@ parameters:
   SigningCertificate: ''
   ExportCommand: ''
   ContinueOnError: false
+  AzureServiceConnectionName: 'Python Signing'
 
 steps:
 - ${{ if parameters.SigningCertificate }}:
   - powershell: |
+      # Install sign tool
       dotnet tool install --global --prerelease sign
       $signtool = (gcm sign -EA SilentlyContinue).Source
       if (-not $signtool) {
@@ -32,6 +34,30 @@ steps:
     env:
       EXPORT_COMMAND: ${{ parameters.ExportCommand }}
 
+  - ${{ if parameters.AzureServiceConnectionName }}:
+    # We sign in once with the AzureCLI task, as it uses OIDC to obtain a
+    # temporary token. But the task also logs out, and so we save the token and
+    # use it to log in persistently (for the rest of the build).
+    - task: AzureCLI@2
+      displayName: 'Authenticate signing tools (1/2)'
+      inputs:
+        azureSubscription: ${{ parameters.AzureServiceConnectionName }}
+        scriptType: 'ps'
+        scriptLocation: 'inlineScript'
+        inlineScript: |
+          "##vso[task.setvariable variable=AZURE_CLIENT_ID;issecret=true]${env:servicePrincipalId}"
+          "##vso[task.setvariable variable=AZURE_ID_TOKEN;issecret=true]${env:idToken}"
+          "##vso[task.setvariable variable=AZURE_TENANT_ID;issecret=true]${env:tenantId}"
+        addSpnToEnvironment: true
+
+    - powershell: >
+        az login --service-principal
+        -u $(AZURE_CLIENT_ID)
+        --tenant $(AZURE_TENANT_ID)
+        --allow-no-subscriptions
+        --federated-token $(AZURE_ID_TOKEN)
+      displayName: 'Authenticate signing tools (2/2)'
+
   - ${{ if parameters.Include }}:
     - powershell: |
         if ("${{ parameters.Exclude }}") {
@@ -58,9 +84,6 @@ steps:
       env:
         TRUSTED_SIGNING_CMD: $(__TrustedSigningCmd)
         TRUSTED_SIGNING_ARGS: $(__TrustedSigningArgs)
-        AZURE_TENANT_ID: $(TrustedSigningTenantId)
-        AZURE_CLIENT_ID: $(TrustedSigningClientId)
-        AZURE_CLIENT_SECRET: $(TrustedSigningSecret)
         ${{ if parameters.Filter }}:
           FILTER: ${{ parameters.Filter }}