diff --git a/extensions/ql-vscode/src/databases/local-databases/database-item-impl.ts b/extensions/ql-vscode/src/databases/local-databases/database-item-impl.ts
index 1c4adfc7e04..fa37938fd39 100644
--- a/extensions/ql-vscode/src/databases/local-databases/database-item-impl.ts
+++ b/extensions/ql-vscode/src/databases/local-databases/database-item-impl.ts
@@ -207,7 +207,6 @@ export class DatabaseItemImpl implements DatabaseItem {
         return pathsEqual(
           databasePath,
           join(testdir, `${testdirbase}.testproj`),
-          process.platform,
         );
       }
     } catch {
diff --git a/extensions/ql-vscode/src/databases/local-databases/database-manager.ts b/extensions/ql-vscode/src/databases/local-databases/database-manager.ts
index 68e2b53191b..d57f0b73101 100644
--- a/extensions/ql-vscode/src/databases/local-databases/database-manager.ts
+++ b/extensions/ql-vscode/src/databases/local-databases/database-manager.ts
@@ -652,7 +652,7 @@ export class DatabaseManager extends DisposableObject {
   private isExtensionControlledLocation(uri: vscode.Uri) {
     const storageUri = this.ctx.storageUri || this.ctx.globalStorageUri;
     if (storageUri) {
-      return containsPath(storageUri.fsPath, uri.fsPath, process.platform);
+      return containsPath(storageUri.fsPath, uri.fsPath);
     }
     return false;
   }
diff --git a/extensions/ql-vscode/src/pure/files.ts b/extensions/ql-vscode/src/pure/files.ts
index 5b3d38d0d69..67dd837b3f5 100644
--- a/extensions/ql-vscode/src/pure/files.ts
+++ b/extensions/ql-vscode/src/pure/files.ts
@@ -1,5 +1,5 @@
 import { pathExists, stat, readdir, opendir } from "fs-extra";
-import { join, resolve } from "path";
+import { isAbsolute, join, relative, resolve } from "path";
 
 /**
  * Recursively finds all .ql files in this set of Uris.
@@ -51,36 +51,32 @@ export async function getDirectoryNamesInsidePath(
   return dirNames;
 }
 
-function normalizePath(path: string, platform: NodeJS.Platform): string {
+function normalizePath(path: string): string {
   // On Windows, "C:/", "C:\", and "c:/" are all equivalent. We need
   // to normalize the paths to ensure they all get resolved to the
   // same format. On Windows, we also need to do the comparison
   // case-insensitively.
   path = resolve(path);
-  if (platform === "win32") {
+  if (process.platform === "win32") {
     path = path.toLowerCase();
   }
   return path;
 }
 
-export function pathsEqual(
-  path1: string,
-  path2: string,
-  platform: NodeJS.Platform,
-): boolean {
-  return normalizePath(path1, platform) === normalizePath(path2, platform);
+export function pathsEqual(path1: string, path2: string): boolean {
+  return normalizePath(path1) === normalizePath(path2);
 }
 
 /**
- * Returns true if path1 contains path2.
+ * Returns true if `parent` contains `child`, or if they are equal.
  */
-export function containsPath(
-  path1: string,
-  path2: string,
-  platform: NodeJS.Platform,
-): boolean {
-  return normalizePath(path2, platform).startsWith(
-    normalizePath(path1, platform),
+export function containsPath(parent: string, child: string): boolean {
+  const relativePath = relative(parent, child);
+  return (
+    !relativePath.startsWith("..") &&
+    // On windows, if the two paths are in different drives, then the
+    // relative path will be an absolute path to the other drive.
+    !isAbsolute(relativePath)
   );
 }
 
diff --git a/extensions/ql-vscode/test/matchers/toEqualPath.ts b/extensions/ql-vscode/test/matchers/toEqualPath.ts
index d598fcf981a..2e828cb7b03 100644
--- a/extensions/ql-vscode/test/matchers/toEqualPath.ts
+++ b/extensions/ql-vscode/test/matchers/toEqualPath.ts
@@ -10,7 +10,7 @@ const toEqualPath: MatcherFunction<[expectedPath: unknown]> = function (
     throw new Error("These must be of type string!");
   }
 
-  const pass = pathsEqual(actual, expectedPath, process.platform);
+  const pass = pathsEqual(actual, expectedPath);
   if (pass) {
     return {
       message: () =>
diff --git a/extensions/ql-vscode/test/unit-tests/pure/files.test.ts b/extensions/ql-vscode/test/unit-tests/pure/files.test.ts
index 0b51ab88cd0..3e2a5a65d49 100644
--- a/extensions/ql-vscode/test/unit-tests/pure/files.test.ts
+++ b/extensions/ql-vscode/test/unit-tests/pure/files.test.ts
@@ -204,102 +204,142 @@ describe("pathsEqual", () => {
         return;
       }
 
-      expect(pathsEqual(path1, path2, platform)).toEqual(expected);
+      expect(pathsEqual(path1, path2)).toEqual(expected);
     },
   );
 });
 
 describe("containsPath", () => {
   const testCases: Array<{
-    path1: string;
-    path2: string;
+    parent: string;
+    child: string;
     platform: NodeJS.Platform;
     expected: boolean;
   }> = [
     {
-      path1:
+      parent:
         "/home/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript",
-      path2:
+      child:
         "/home/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript/example.ql",
       platform: "linux",
       expected: true,
     },
     {
-      path1:
+      parent:
         "/HOME/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript",
-      path2:
+      child:
         "/home/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript/example.ql",
       platform: "linux",
       expected: false,
     },
     {
-      path1:
+      parent:
         "/home/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript/example.ql",
-      path2:
+      child:
         "/home/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript",
       platform: "linux",
       expected: false,
     },
     {
-      path1:
+      parent:
+        "/home/github/projects/vscode-codeql-starter/codeql-custom-queries-java",
+      child:
+        "/home/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript",
+      platform: "linux",
+      expected: false,
+    },
+    {
+      parent:
+        "/home/github/projects/vscode-codeql-starter/codeql-custom-queries-java",
+      child:
+        "/home/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript/example.ql",
+      platform: "linux",
+      expected: false,
+    },
+    {
+      parent:
         "C:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript",
-      path2:
+      child:
         "C:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript/example.ql",
       platform: "win32",
       expected: true,
     },
     {
-      path1:
+      parent:
         "C:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript",
-      path2:
+      child:
         "c:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript/example.ql",
       platform: "win32",
       expected: true,
     },
     {
-      path1:
+      parent:
         "C:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript",
-      path2:
+      child:
+        "C:/USERS/GITHUB/PROJECTS/VSCODE-CODEQL-STARTER/CODEQL-CUSTOM-QUERIES-JAVASCRIPT/EXAMPLE.QL",
+      platform: "win32",
+      expected: true,
+    },
+    {
+      parent:
+        "C:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript",
+      child:
         "D:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript/example.ql",
       platform: "win32",
       expected: false,
     },
     {
-      path1:
+      parent:
         "C:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript/example.ql",
-      path2:
+      child:
         "C:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript",
       platform: "win32",
       expected: false,
     },
     {
-      path1:
+      parent:
         "C:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript",
-      path2:
+      child:
         "C:\\Users\\github\\projects\\vscode-codeql-starter\\codeql-custom-queries-javascript\\example.ql",
       platform: "win32",
       expected: true,
     },
     {
-      path1:
+      parent:
         "C:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript",
-      path2:
+      child:
         "D:\\Users\\github\\projects\\vscode-codeql-starter\\codeql-custom-queries-javascript\\example.ql",
       platform: "win32",
       expected: false,
     },
+    {
+      parent:
+        "C:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-java",
+      child:
+        "C:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript",
+      platform: "win32",
+      expected: false,
+    },
+    {
+      parent:
+        "C:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-java",
+      child:
+        "C:/Users/github/projects/vscode-codeql-starter/codeql-custom-queries-javascript/example.ql",
+      platform: "win32",
+      expected: false,
+    },
   ];
 
   test.each(testCases)(
-    "$path1 contains $path2 on $platform = $expected",
-    ({ path1, path2, platform, expected }) => {
+    "$parent contains $child on $platform = $expected",
+    ({ parent, child, platform, expected }) => {
       if (platform !== process.platform) {
         // We're using the platform-specific path.resolve, so we can't really run
         // these tests on all platforms.
         return;
       }
 
-      expect(containsPath(path1, path2, platform)).toEqual(expected);
+      expect(containsPath(parent, child)).toEqual(expected);
     },
   );
 });