diff --git a/constructor/signing.py b/constructor/signing.py
index dcfd116ab..89bcb8854 100644
--- a/constructor/signing.py
+++ b/constructor/signing.py
@@ -193,7 +193,7 @@ def verify_signature(self, installer_file: str | Path):
             logger.error("Could not verify signature: PowerShell not found.")
             return
         command = (
-            f"$sig = Get-AuthenticodeSignature -LiteralPath {installer_file};"
+            f"$sig = Get-AuthenticodeSignature -LiteralPath '{installer_file}';"
             "$sig.Status.value__;"
             "$sig.StatusMessage"
         )
diff --git a/examples/azure_signtool/construct.yaml b/examples/azure_signtool/construct.yaml
index 96498a702..2ca0395cd 100644
--- a/examples/azure_signtool/construct.yaml
+++ b/examples/azure_signtool/construct.yaml
@@ -3,7 +3,7 @@
 
 name: Signed_AzureSignTool
 version: 1.0.0
-installer_type: exe
+installer_type: [exe, msi]
 channels:
   - https://repo.anaconda.com/pkgs/main/
 specs:
diff --git a/news/1273-fix-msi-signing-spaces b/news/1273-fix-msi-signing-spaces
new file mode 100644
index 000000000..b8c6d3a9c
--- /dev/null
+++ b/news/1273-fix-msi-signing-spaces
@@ -0,0 +1,19 @@
+### Enhancements
+
+* <news item>
+
+### Bug fixes
+
+* Fix `AzureSignTool` signature verification failing for installer paths that contain spaces. (#1273)
+
+### Deprecations
+
+* <news item>
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>
diff --git a/tests/test_signing.py b/tests/test_signing.py
new file mode 100644
index 000000000..a109d21be
--- /dev/null
+++ b/tests/test_signing.py
@@ -0,0 +1,23 @@
+import sys
+
+import pytest
+
+from constructor.signing import AzureSignTool
+
+
+@pytest.mark.skipif(sys.platform != "win32", reason="Windows only")
+def test_azure_verify_signature_quotes_path_with_spaces(mocker):
+    """Test that installer paths containing spaces are quoted in the PowerShell command."""
+    tool = AzureSignTool()
+    installer = r"C:\Users\runner\Some Product\foo.msi"
+
+    mocker.patch("constructor.signing.shutil.which", return_value="powershell")
+    mock_run = mocker.patch("constructor.signing.run")
+    mock_run.return_value.stderr = ""
+    mock_run.return_value.stdout = "0\nSignature verified.\n"
+
+    tool.verify_signature(installer)
+
+    # argv passed to run() is ["powershell", "-c", command]
+    command = mock_run.call_args.args[0][2]
+    assert f"-LiteralPath '{installer}'" in command