diff --git a/.github/workflows/build_windows.yaml b/.github/workflows/build_windows.yaml
index 1224ee67..9044adc1 100644
--- a/.github/workflows/build_windows.yaml
+++ b/.github/workflows/build_windows.yaml
@@ -35,6 +35,8 @@ jobs:
         environment: ${{ inputs.sign && 'packages.element.io' || '' }}
         env:
             SIGNTOOL_PATH: "C:/Program Files (x86)/Windows Kits/10/bin/10.0.22000.0/x86/signtool.exe"
+            # electron-windows-sign of electron-winstaller uses a different env var
+            WINDOWS_SIGNTOOL_PATH: "C:/Program Files (x86)/Windows Kits/10/bin/10.0.22000.0/x86/signtool.exe"
         steps:
             - uses: nbucic/variable-mapper@0673f6891a0619ba7c002ecfed0f9f4f39017b6f
               id: config