diff --git a/package.json b/package.json
index eeae4ea..db4dd2b 100644
--- a/package.json
+++ b/package.json
@@ -47,8 +47,10 @@
     "precoverage": "npm run test",
     "coverage": "nyc report --reporter=text-lcov | coveralls",
     "pretest": "npm run lint",
-    "test": "nyc --reporter=lcov --reporter=text-summary npm run test:mocha",
+    "test": "nyc --reporter=lcov --reporter=text-summary npm run test:mocha:all",
     "test:mocha": "mocha --reporter dot",
+    "test:mocha:legacy": "NO_SET=1 mocha --reporter dot",
+    "test:mocha:all": "npm run test:mocha && npm run test:mocha:legacy",
     "test:watch": "mocha --reporter min --watch",
     "test:chrome": "karma start"
   }
diff --git a/test/core/seq.test.js b/test/core/seq.test.js
index 921233c..719bdc9 100644
--- a/test/core/seq.test.js
+++ b/test/core/seq.test.js
@@ -1,56 +1,43 @@
 "use strict";
 
-testSetUsage(function setUsage(api) {
-  it(api.setTestDescription("Parsimmon.seq"), function() {
-    var parser = Parsimmon.seq(
-      Parsimmon.string("("),
-      Parsimmon.regexp(/[^)]/)
-        .many()
-        .map(function(xs) {
-          return xs.join("");
-        }),
-      Parsimmon.string(")")
-    );
+it("Parsimmon.seq", function() {
+  var parser = Parsimmon.seq(
+    Parsimmon.string("("),
+    Parsimmon.regexp(/[^)]/)
+      .many()
+      .map(function(xs) {
+        return xs.join("");
+      }),
+    Parsimmon.string(")")
+  );
 
-    assert.deepEqual(
-      api.scopeSet(function scopeSet() {
-        return parser.parse("(string between parens)");
-      }).value,
-      ["(", "string between parens", ")"]
-    );
+  assert.deepEqual(parser.parse("(string between parens)").value, [
+    "(",
+    "string between parens",
+    ")"
+  ]);
 
-    assert.deepEqual(
-      api.scopeSet(function scopeSet() {
-        return parser.parse("(string");
-      }),
-      {
-        status: false,
-        index: {
-          offset: 7,
-          line: 1,
-          column: 8
-        },
-        expected: ["')'", "/[^)]/"]
-      }
-    );
+  assert.deepEqual(parser.parse("(string"), {
+    status: false,
+    index: {
+      offset: 7,
+      line: 1,
+      column: 8
+    },
+    expected: ["')'", "/[^)]/"]
+  });
 
-    assert.deepEqual(
-      api.scopeSet(function scopeSet() {
-        return parser.parse("starts wrong (string between parens)");
-      }),
-      {
-        status: false,
-        index: {
-          offset: 0,
-          line: 1,
-          column: 1
-        },
-        expected: ["'('"]
-      }
-    );
+  assert.deepEqual(parser.parse("starts wrong (string between parens)"), {
+    status: false,
+    index: {
+      offset: 0,
+      line: 1,
+      column: 1
+    },
+    expected: ["'('"]
+  });
 
-    assert.throws(function() {
-      Parsimmon.seq("not a parser");
-    });
+  assert.throws(function() {
+    Parsimmon.seq("not a parser");
   });
 });
diff --git a/test/setup.js b/test/setup.js
index aa9fbfc..ff8fe4b 100644
--- a/test/setup.js
+++ b/test/setup.js
@@ -17,6 +17,12 @@
   delete Object.prototype.__magic__;
 })();
 
+if (typeof process !== "undefined") {
+  if (process.env.NO_SET) {
+    delete globalThis.Set;
+  }
+}
+
 // Karma loads these for us
 if (typeof require !== "undefined") {
   globalThis.assert = require("chai").assert;
@@ -28,32 +34,3 @@ globalThis.equivalentParsers = function equivalentParsers(p1, p2, inputs) {
     assert.deepEqual(p1.parse(inputs[i]), p2.parse(inputs[i]));
   }
 };
-
-// In order to test a scenario where "Set" is not available, we need
-// to scope out a execution without Set only for code under test. The
-// chai libraries will error if Set doesnt exist when assertions run.
-globalThis.testSetUsage = function testSetUsage(innerFn) {
-  var origSet = globalThis.Set;
-  var setAvailableScenarios = [true, false];
-  for (var i = 0; i < setAvailableScenarios.length; i++) {
-    var api = {
-      setTestDescription: function setTestDescription(desc) {
-        if (!setAvailableScenarios[i]) {
-          return desc + " (no Set)";
-        }
-        return desc;
-      },
-      scopeSet: function scopeSet(fn) {
-        if (!setAvailableScenarios[i]) {
-          delete globalThis.Set;
-        }
-        var result = fn();
-        if (!setAvailableScenarios[i]) {
-          globalThis.Set = origSet;
-        }
-        return result;
-      }
-    };
-    innerFn(api);
-  }
-};