diff --git a/backend/src/langs.ts b/backend/src/langs.ts
index 488171b..69c7283 100644
--- a/backend/src/langs.ts
+++ b/backend/src/langs.ts
@@ -1629,6 +1629,21 @@ PLEASE GIVE UP
         "curl -sS 'https://registry.npmjs.org/-/v1/search?text=NAME' | jq -r '.objects | map(.package.name) | .[]'",
     },
     template: `console.log("Hello, world!");
+`,
+  },
+  jq: {
+    name: "jq",
+    repl: "echo 'Reading from stdin...' >&2 && while true; do jq .; done",
+    input: `{"foo":"bar"}`,
+    output: `"foo": "bar"`,
+    main: "main.jq",
+    run: `echo 'Reading from stdin...' >&2 && while true; do jq "$(< main.jq)"; done`,
+    helloInput: `{}`,
+    // This test doesn't actually test anything, because "Hello,
+    // world" is already printed before anything is sent to the repl,
+    // but we can't do any better.
+    runReplOutput: `"Hello, world!"`,
+    template: `"Hello, world!"
 `,
   },
   julia: {
diff --git a/backend/src/test-runner.ts b/backend/src/test-runner.ts
index 9de15c5..4cfb26c 100644
--- a/backend/src/test-runner.ts
+++ b/backend/src/test-runner.ts
@@ -7,6 +7,7 @@ import { Moment } from "moment";
 import * as moment from "moment";
 import PQueue from "p-queue";
 import * as rimraf from "rimraf";
+import stripAnsi = require("strip-ansi");
 import { v4 as getUUID } from "uuid";
 
 import * as api from "./api";
@@ -187,7 +188,9 @@ class Test {
     return await this.wait(`output ${JSON.stringify(pattern)}`, (msg: any) => {
       const prevLength = output.length;
       if (msg.event === "terminalOutput") {
-        output += msg.output;
+        // Applying stripAnsi here is wrong because escape sequences
+        // could be split across multiple messages. Who cares?
+        output += stripAnsi(msg.output);
       }
       if (typeof maxLength === "number") {
         return (
diff --git a/package.json b/package.json
index c58174e..e19f307 100644
--- a/package.json
+++ b/package.json
@@ -38,6 +38,7 @@
     "parse-passwd": "^1.0.0",
     "rimraf": "^3.0.2",
     "shell-quote": "^1.7.2",
+    "strip-ansi": "^6.0.0",
     "style-loader": "^1.2.1",
     "ts-loader": "^7.0.5",
     "typescript": "^3.9.5",
diff --git a/scripts/docker-install-phase3b.bash b/scripts/docker-install-phase3b.bash
index 72c57d7..9e46d98 100755
--- a/scripts/docker-install-phase3b.bash
+++ b/scripts/docker-install-phase3b.bash
@@ -64,6 +64,9 @@ intercal
 clang-format
 default-jdk
 
+# jq
+jq
+
 # Julia
 julia
 
diff --git a/yarn.lock b/yarn.lock
index 27ba20a..6e944d5 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1152,6 +1152,11 @@ ansi-regex@^4.1.0:
   resolved "https://registry.yarnpkg.com/ansi-regex/-/ansi-regex-4.1.0.tgz#8b9f8f08cf1acb843756a839ca8c7e3168c51997"
   integrity sha512-1apePfXM1UOSqw0o9IiFAovVz9M5S1Dg+4TrDwfMewQ6p/rmMueb7tWZjQ1rx4Loy1ArBggoqGpfqqdI4rondg==
 
+ansi-regex@^5.0.0:
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/ansi-regex/-/ansi-regex-5.0.0.tgz#388539f55179bf39339c81af30a654d69f87cb75"
+  integrity sha512-bY6fj56OUQ0hU1KjFNDQuJFezqKdrAyFdIevADiqrWHwSlbmBNMHp5ak2f40Pm8JTFyM2mqxkG6ngkHO11f/lg==
+
 ansi-styles@^3.2.0, ansi-styles@^3.2.1:
   version "3.2.1"
   resolved "https://registry.yarnpkg.com/ansi-styles/-/ansi-styles-3.2.1.tgz#41fbb20243e50b12be0f04b8dedbf07520ce841d"
@@ -4570,6 +4575,13 @@ strip-ansi@^5.0.0, strip-ansi@^5.1.0, strip-ansi@^5.2.0:
   dependencies:
     ansi-regex "^4.1.0"
 
+strip-ansi@^6.0.0:
+  version "6.0.0"
+  resolved "https://registry.yarnpkg.com/strip-ansi/-/strip-ansi-6.0.0.tgz#0b1571dd7669ccd4f3e06e14ef1eed26225ae532"
+  integrity sha512-AuvKTrTfQNYNIctbR1K/YGTR1756GycPsg7b9bdV9Duqur4gv6aKqHXah67Z8ImS7WEz5QVcOtlfW2rZEugt6w==
+  dependencies:
+    ansi-regex "^5.0.0"
+
 strip-bom@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/strip-bom/-/strip-bom-3.0.0.tgz#2334c18e9c759f7bdd56fdef7e9ae3d588e68ed3"