diff --git a/packages/app/src/workspace/file-open/index.test.ts b/packages/app/src/workspace/file-open/index.test.ts
index 6a31ac6ab..d7d2dd397 100644
--- a/packages/app/src/workspace/file-open/index.test.ts
+++ b/packages/app/src/workspace/file-open/index.test.ts
@@ -140,6 +140,37 @@ describe("resolveWorkspaceFilePaths", () => {
     expect(
       resolveWorkspaceFilePaths({ path: "~/notes.md", workspaceRoot: "/Users/me/repo" }),
     ).toBeNull();
+    expect(resolveWorkspaceFilePaths({ path: "~", workspaceRoot: "/Users/me/repo" })).toBeNull();
+  });
+
+  it("treats filenames that merely start with ~ as workspace-relative", () => {
+    expect(resolveWorkspaceFilePaths({ path: "~env.ts", workspaceRoot: "/Users/me/repo" })).toEqual(
+      {
+        absolutePath: "/Users/me/repo/~env.ts",
+        relativePath: "~env.ts",
+      },
+    );
+  });
+
+  it("matches Windows workspace paths case-insensitively", () => {
+    expect(
+      resolveWorkspaceFilePaths({
+        path: "C:\\Users\\Me\\Repo\\src\\app.ts",
+        workspaceRoot: "c:\\users\\me\\repo",
+      }),
+    ).toEqual({
+      absolutePath: "C:/Users/Me/Repo/src/app.ts",
+      relativePath: "src/app.ts",
+    });
+  });
+
+  it("treats a case-only difference from the Windows root as the root itself", () => {
+    expect(
+      resolveWorkspaceFilePaths({
+        path: "C:\\Users\\Me\\Repo",
+        workspaceRoot: "c:\\users\\me\\repo",
+      }),
+    ).toBeNull();
   });
 
   it("returns null when the workspace root is not absolute", () => {
diff --git a/packages/app/src/workspace/file-open/index.ts b/packages/app/src/workspace/file-open/index.ts
index 4a14a78a5..a823edd5d 100644
--- a/packages/app/src/workspace/file-open/index.ts
+++ b/packages/app/src/workspace/file-open/index.ts
@@ -113,6 +113,22 @@ function normalizeRelativePath(value: string): string | null {
   return normalized || null;
 }
 
+function isWindowsPath(value: string): boolean {
+  return /^[A-Za-z]:\//.test(value);
+}
+
+function pathsEqual(left: string, right: string): boolean {
+  return isWindowsPath(left) || isWindowsPath(right)
+    ? left.toLowerCase() === right.toLowerCase()
+    : left === right;
+}
+
+function startsWithPath(value: string, prefix: string): boolean {
+  return isWindowsPath(value) || isWindowsPath(prefix)
+    ? value.toLowerCase().startsWith(prefix.toLowerCase())
+    : value.startsWith(prefix);
+}
+
 export interface ResolvedWorkspaceFilePaths {
   /** Absolute path on the host, suitable for opening in an editor / file manager. */
   absolutePath: string;
@@ -140,16 +156,17 @@ export function resolveWorkspaceFilePaths(input: {
     if (!normalizedFile) {
       return null;
     }
-    if (normalizedFile === workspaceRoot) {
+    if (pathsEqual(normalizedFile, workspaceRoot)) {
       return null;
     }
-    const relativePath = normalizedFile.startsWith(`${workspaceRoot}/`)
-      ? normalizedFile.slice(workspaceRoot.length + 1)
+    const prefix = `${workspaceRoot}/`;
+    const relativePath = startsWithPath(normalizedFile, prefix)
+      ? normalizedFile.slice(prefix.length)
       : null;
     return { absolutePath: normalizedFile, relativePath };
   }
 
-  if (filePath.startsWith("~")) {
+  if (filePath === "~" || filePath.startsWith("~/")) {
     return null;
   }