diff --git a/dom/quota/test/unit/head-shared.js b/dom/quota/test/unit/head-shared.js
index 991ead6b6bc6..41fccb2f82d8 100644
--- a/dom/quota/test/unit/head-shared.js
+++ b/dom/quota/test/unit/head-shared.js
@@ -316,6 +316,12 @@ function getRelativeFile(relativePath, baseFile) {
   }
 
   let file = baseFile.clone();
+
+  if (Services.appinfo.OS === "WINNT") {
+    let winFile = file.QueryInterface(Ci.nsILocalFileWin);
+    winFile.useDOSDevicePathSyntax = true;
+  }
+
   relativePath.split("/").forEach(function(component) {
     if (component == "..") {
       file = file.parent;
diff --git a/dom/quota/test/unit/test_validOrigins.js b/dom/quota/test/unit/test_validOrigins.js
index ad0d742a1537..8797b9799fff 100644
--- a/dom/quota/test/unit/test_validOrigins.js
+++ b/dom/quota/test/unit/test_validOrigins.js
@@ -8,29 +8,82 @@
 // exception (and potentially MOZ_ASSERT under debug builds). Handling of
 // obsolete or invalid origins is handled in other test files.
 async function testSteps() {
-  const testingURLs = [
+  const basePath = "storage/default/";
+  const longExampleOriginSubstring = "a".repeat(
+    255 - "https://example..com".length
+  );
+  const origins = [
     // General
-    "https://example.com",
-    "https://smaug----.github.io/",
+    {
+      dirName: "https+++example.com",
+      url: "https://example.com",
+    },
+    {
+      dirName: "https+++smaug----.github.io",
+      url: "https://smaug----.github.io/",
+    },
     // About
-    "about:home",
-    "about:reader",
+    {
+      dirName: "about+home",
+      url: "about:home",
+    },
+    {
+      dirName: "about+reader",
+      url: "about:reader",
+    },
     // IPv6
-    "https://[::]",
-    "https://[ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff]",
-    "http://[2010:836B:4179::836B:4179]:80",
-    "https://[::FFFF:129.144.52.38]",
+    {
+      dirName: "https+++[++]",
+      url: "https://[::]",
+    },
+    {
+      dirName: "https+++[ffff+ffff+ffff+ffff+ffff+ffff+ffff+ffff]",
+      url: "https://[ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff]",
+    },
+    {
+      dirName: "http+++[2010+836b+4179++836b+4179]",
+      url: "http://[2010:836B:4179::836B:4179]:80",
+    },
+    {
+      dirName: "https+++[++ffff+8190+3426]",
+      url: "https://[::FFFF:129.144.52.38]",
+    },
+    // MAX_PATH on Windows (260); storage/default/https+++example.{a....a}.com
+    // should have already exceeded the MAX_PATH limitation on Windows.
+    // There is a limitation (255) for each component on Windows so that we can
+    // only let the component be 255 chars and expect the wwhole path to be
+    // greater then 260.
+    {
+      dirName: `https+++example.${longExampleOriginSubstring}.com`,
+      url: `https://example.${longExampleOriginSubstring}.com`,
+    },
+    // EndingWithPeriod
+    {
+      dirName: "https+++example.com.",
+      url: "https://example.com.",
+    },
   ];
 
-  for (let testingURL of testingURLs) {
-    info("Testing " + testingURL);
+  for (let origin of origins) {
+    info(`Testing ${origin.url}`);
+
     try {
-      let request = initStorageAndOrigin(getPrincipal(testingURL), "default");
+      let request = initStorageAndOrigin(getPrincipal(origin.url), "default");
       await requestFinished(request);
 
       ok(true, "Should not have thrown");
     } catch (ex) {
       ok(false, "Should not have thrown");
     }
+
+    let dir = getRelativeFile(basePath + origin.dirName);
+    ok(dir.exists(), "Origin was created");
+    ok(
+      origin.dirName === dir.leafName,
+      `Origin ${origin.dirName} was created expectedly`
+    );
   }
+
+  let request = clear();
+  await requestFinished(request);
 }