diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index f9e8fe8e..bef8f17d 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -98,6 +98,8 @@ jobs:
         shell: bash
 
       - name: Run tests
+        env:
+          MANIM_NOTEBOOK_TEST_CLIPBOARD_TIMEOUT_MS: "3000"
         run: |
           if [ "$RUNNER_OS" == "Linux" ]; then
             # Start an X virtual framebuffer (Xvfb) server, which emulates a
diff --git a/tests/preview.test.ts b/tests/preview.test.ts
index fef58efd..eda96791 100644
--- a/tests/preview.test.ts
+++ b/tests/preview.test.ts
@@ -29,7 +29,12 @@ describe("Previewing", function () {
     });
   });
 
-  it("Can preview laggy scene", async () => {
+  it("Can preview laggy scene", async function () {
+    if (process.env.CI === "true" && process.platform === "linux") {
+      // Linux CI runners can be significantly slower for this GPU-heavy scene
+      this.timeout(120_000);
+    }
+
     const editor = await window.showTextDocument(uriInWorkspace("laggy.py"));
     const queue: { line: number; waitForStrings: string[]; resolve: () => void }[] = [];
     let wantToStopListening = false;
@@ -40,7 +45,8 @@ describe("Previewing", function () {
         return;
       }
       if (queue.length === 0) {
-        throw new Error("Listening to terminal output, but nothing in queue to check against");
+        // Ignore unrelated output from concurrent terminal activity
+        return;
       }
 
       const { waitForStrings } = queue[0];
@@ -56,10 +62,13 @@ describe("Previewing", function () {
 
     async function testPreviewAtLine(line: number, waitForStrings: string[]) {
       goToLine(editor, line);
-      await commands.executeCommand("manim-notebook.previewManimCell");
-      await new Promise<void>((resolve) => {
-        queue.push({ line, waitForStrings, resolve });
+
+      const done = new Promise<void>((resolve) => {
+        queue.push({ line, waitForStrings: [...waitForStrings], resolve });
       });
+
+      await commands.executeCommand("manim-notebook.previewManimCell");
+      await done;
     }
 
     await testPreviewAtLine(8, ["ShowCreationVGroup", "In [2]:"]);
diff --git a/tests/utils/manimInstaller.ts b/tests/utils/manimInstaller.ts
index 7e207ca4..c677d9a8 100644
--- a/tests/utils/manimInstaller.ts
+++ b/tests/utils/manimInstaller.ts
@@ -138,6 +138,9 @@ export class ManimInstaller {
       await this.runWithVenvBin("pip install PyOpenGL");
     }
 
+    // Remove once this is merged: https://github.com/3b1b/manim/pull/2439/
+    await this.runWithVenvBin("pip install trimesh pywavefront");
+
     console.log("🔧 Additional dependencies successfully installed");
   }
 
diff --git a/tests/utils/testRunner.ts b/tests/utils/testRunner.ts
index 3d159910..b1d32fa2 100644
--- a/tests/utils/testRunner.ts
+++ b/tests/utils/testRunner.ts
@@ -19,7 +19,7 @@ import * as path from "path";
 import "source-map-support/register";
 import "./prototype";
 
-import { Uri, extensions, window, workspace } from "vscode";
+import { ConfigurationTarget, Uri, extensions, window, workspace } from "vscode";
 
 const WORKSPACE_ROOT: string = workspace.workspaceFolders![0].uri.fsPath;
 
@@ -68,6 +68,8 @@ export function run(): Promise<void> {
         console.log("💠 Tests requested via npm script");
       }
 
+      await configureClipboardTimeoutForCI();
+
       // open any python file to trigger extension activation
       await window.showTextDocument(uriInWorkspace("basic.py"));
 
@@ -95,6 +97,26 @@ export function run(): Promise<void> {
   });
 }
 
+/**
+ * In CI, test execution can be slower and restoring clipboard contents may
+ * race with command handling. Increase timeout to reduce flaky tests.
+ */
+async function configureClipboardTimeoutForCI(): Promise<void> {
+  if (process.env.CI !== "true") {
+    return;
+  }
+
+  const timeoutMs = Number(process.env.MANIM_NOTEBOOK_TEST_CLIPBOARD_TIMEOUT_MS ?? "2000");
+  if (!Number.isFinite(timeoutMs) || timeoutMs <= 0) {
+    throw new Error("MANIM_NOTEBOOK_TEST_CLIPBOARD_TIMEOUT_MS must be a positive number");
+  }
+
+  await workspace
+    .getConfiguration("manim-notebook")
+    .update("clipboardTimeout", timeoutMs, ConfigurationTarget.Workspace);
+  console.log(`💠 CI override: manim-notebook.clipboardTimeout=${timeoutMs}ms`);
+}
+
 /**
  * Waits until the Manim Notebook extension is activated.
  */