diff --git a/spec/compiler/passes/compute-params.spec.js b/spec/compiler/passes/compute-params.spec.js
new file mode 100644
index 0000000..5903702
--- /dev/null
+++ b/spec/compiler/passes/compute-params.spec.js
@@ -0,0 +1,200 @@
+describe("compiler pass |computeParams|", function() {
+  function pass(ast) {
+    PEG.compiler.passes.computeVarNames(ast);
+    PEG.compiler.passes.computeParams(ast);
+  }
+
+  function ruleDetails(details) { return { rules: [details] }; }
+
+  function expressionDetails(details) {
+    return ruleDetails({ expression: details });
+  }
+
+  function innerExpressionDetails(details) {
+    return expressionDetails({ expression: details });
+  }
+
+  describe("basic cases", function() {
+    it("computes params for an action", function() {
+      expect(pass).toChangeAST('start = a:"a" { }', expressionDetails({
+        params: { a: "result0" }
+      }));
+    });
+
+    it("computes params for a semantic and", function() {
+      expect(pass).toChangeAST('start = a:"a" &{ }', expressionDetails({
+        elements: [
+          {},
+          { params: { a: "result0" } }
+        ]
+      }));
+    });
+
+    it("computes params for a semantic not", function() {
+      expect(pass).toChangeAST('start = a:"a" !{ }', expressionDetails({
+        elements: [
+          {},
+          { params: { a: "result0" } }
+        ]
+      }));
+    });
+  });
+
+  describe("recursive walk", function() {
+    it("computes params for a choice", function() {
+      expect(pass).toChangeAST(
+        'start = a:"a" { } / "b" / "c"',
+        expressionDetails({
+          alternatives: [{ params: { a: "result0" } }, {}, {}]
+        })
+      );
+      expect(pass).toChangeAST(
+        'start = "a" / "b" / c:"c" { }',
+        expressionDetails({
+          alternatives: [{}, {}, { params: { c: "result0" } }]
+        })
+      );
+    });
+
+    it("computes params for a sequence", function() {
+      expect(pass).toChangeAST(
+        'start = (a:"a" { }) "b" "c"',
+        expressionDetails({
+          elements: [{ params: { a: "result0" } }, {}, {}]
+        })
+      );
+      expect(pass).toChangeAST(
+        'start = "a" "b" (c:"c" { })',
+        expressionDetails({
+          elements: [{}, {}, { params: { c: "result2" } }]
+        })
+      );
+    });
+
+    it("computes params for a labeled", function() {
+      expect(pass).toChangeAST('start = a:(b:"b" { })', innerExpressionDetails({
+        params: { b: "result0" }
+      }));
+    });
+
+    it("computes params for a simple and", function() {
+      expect(pass).toChangeAST('start = &(a:"a" { })', innerExpressionDetails({
+        params: { a: "result0" }
+      }));
+    });
+
+    it("computes params for a simple not", function() {
+      expect(pass).toChangeAST('start = &(a:"a" { })', innerExpressionDetails({
+        params: { a: "result0" }
+      }));
+    });
+
+    it("computes params for an optional", function() {
+      expect(pass).toChangeAST('start = (a:"a" { })?', innerExpressionDetails({
+        params: { a: "result0" }
+      }));
+    });
+
+    it("computes params for a zero or more", function() {
+      expect(pass).toChangeAST('start = (a:"a" { })*', innerExpressionDetails({
+        params: { a: "result1" }
+      }));
+    });
+
+    it("computes params for a one or more", function() {
+      expect(pass).toChangeAST('start = (a:"a" { })+', innerExpressionDetails({
+        params: { a: "result1" }
+      }));
+    });
+
+    it("computes params for an action", function() {
+      expect(pass).toChangeAST('start = (a:"a" { }) { }', innerExpressionDetails({
+        params: { a: "result0" }
+      }));
+    });
+  });
+
+  describe("scoping", function() {
+    it("creates a new scope for a choice", function() {
+      expect(pass).toChangeAST(
+        'start = (a:"a" / b:"b" / c:"c") { }',
+        expressionDetails({ params: {} })
+      );
+    });
+
+    it("does not create a new scope for a sequence", function() {
+      expect(pass).toChangeAST(
+        'start = a:"a" b:"b" c:"c" { }',
+        expressionDetails({
+          params: { a: "result0[0]", b: "result0[1]", c: "result0[2]" }
+        })
+      );
+      expect(pass).toChangeAST(
+        'start = a:"a" (b:"b" c:"c" d:"d") e:"e"{ }',
+        expressionDetails({
+          params: {
+            a: "result0[0]",
+            b: "result0[1][0]",
+            c: "result0[1][1]",
+            d: "result0[1][2]",
+            e: "result0[2]"
+          }
+        })
+      );
+
+      /*
+       * Regression tests for a bug where e.g. resultVar names like |result10|
+       * were incorrectly treated as names derived from |result1|, leading to
+       * incorrect substitution.
+       */
+      expect(pass).toChangeAST(
+        'start = ("a" "b" "c" "d" "e" "f" "g" "h" "i" j:"j" { })*',
+        innerExpressionDetails({
+          params: { j: "result1[9]" } // Buggy code put "result1[0]0" here.
+        })
+      );
+    });
+
+    it("creates a new scope for a labeled", function() {
+      expect(pass).toChangeAST('start = a:(b:"b") { }', expressionDetails({
+        params: { a: "result0"}
+      }));
+    });
+
+    it("creates a new scope for a simple and", function() {
+      expect(pass).toChangeAST('start = &(a:"a") { }', expressionDetails({
+        params: {}
+      }));
+    });
+
+    it("creates a new scope for a simple not", function() {
+      expect(pass).toChangeAST('start = !(a:"a") { }', expressionDetails({
+        params: {}
+      }));
+    });
+
+    it("creates a new scope for an optional", function() {
+      expect(pass).toChangeAST('start = (a:"a")? { }', expressionDetails({
+        params: {}
+      }));
+    });
+
+    it("creates a new scope for a zero or more", function() {
+      expect(pass).toChangeAST('start = (a:"a")* { }', expressionDetails({
+        params: {}
+      }));
+    });
+
+    it("creates a new scope for a one or more", function() {
+      expect(pass).toChangeAST('start = (a:"a")+ { }', expressionDetails({
+        params: {}
+      }));
+    });
+
+    it("creates a new scope for an action", function() {
+      expect(pass).toChangeAST('start = (a:"a" { }) { }', expressionDetails({
+        params: {}
+      }));
+    });
+  });
+});
diff --git a/spec/compiler/passes/compute-var-names.spec.js b/spec/compiler/passes/compute-var-names.spec.js
index e16c8d4..57eff42 100644
--- a/spec/compiler/passes/compute-var-names.spec.js
+++ b/spec/compiler/passes/compute-var-names.spec.js
@@ -22,61 +22,6 @@ describe("compiler pass |computeVarNames|", function() {
 
   function ruleDetails(details) { return { rules: [details] }; }
 
-  beforeEach(function() {
-    this.addMatchers({
-      toChangeAST: function(grammar, details) {
-        function matchDetails(value, details) {
-          function isArray(value) {
-            return Object.prototype.toString.apply(value) === "[object Array]";
-          }
-
-          function isObject(value) {
-            return value !== null && typeof value === "object";
-          }
-
-          var i, key;
-
-          if (isArray(details)) {
-            if (!isArray(value)) { return false; }
-
-            if (value.length !== details.length) { return false; }
-            for (i = 0; i < details.length; i++) {
-              if (!matchDetails(value[i], details[i])) { return false; }
-            }
-
-            return true;
-          } else if (isObject(details)) {
-            if (!isObject(value)) { return false; }
-
-            for (key in details) {
-              if (!(key in value)) { return false; }
-
-              if (!matchDetails(value[key], details[key])) { return false; }
-            }
-
-            return true;
-          } else {
-            return value === details;
-          }
-        }
-
-        var ast = PEG.parser.parse(grammar);
-
-        this.actual(ast);
-
-        this.message = function() {
-          return "Expected the pass "
-               + (this.isNot ? "not " : "")
-               + "to change the AST " + jasmine.pp(ast) + " "
-               + "to match " + jasmine.pp(details) + ", "
-               + "but it " + (this.isNot ? "did" : "didn't") + ".";
-        };
-
-        return matchDetails(ast, details);
-      }
-    });
-  });
-
   it("computes variable names for a choice", function() {
     expect(pass).toChangeAST('start = &"a" / &"b" / &"c"', ruleDetails({
       resultVars: ["result0"],
diff --git a/spec/helpers.js b/spec/helpers.js
index b866ac8..6b65989 100644
--- a/spec/helpers.js
+++ b/spec/helpers.js
@@ -1 +1,58 @@
-PEG = require("../lib/peg.js");
+if (typeof module !== "undefined") {
+  PEG = require("../lib/peg.js");
+}
+
+beforeEach(function() {
+  this.addMatchers({
+    toChangeAST: function(grammar, details) {
+      function matchDetails(value, details) {
+        function isArray(value) {
+          return Object.prototype.toString.apply(value) === "[object Array]";
+        }
+
+        function isObject(value) {
+          return value !== null && typeof value === "object";
+        }
+
+        var i, key;
+
+        if (isArray(details)) {
+          if (!isArray(value)) { return false; }
+
+          if (value.length !== details.length) { return false; }
+          for (i = 0; i < details.length; i++) {
+            if (!matchDetails(value[i], details[i])) { return false; }
+          }
+
+          return true;
+        } else if (isObject(details)) {
+          if (!isObject(value)) { return false; }
+
+          for (key in details) {
+            if (!(key in value)) { return false; }
+
+            if (!matchDetails(value[key], details[key])) { return false; }
+          }
+
+          return true;
+        } else {
+          return value === details;
+        }
+      }
+
+      var ast = PEG.parser.parse(grammar);
+
+      this.actual(ast);
+
+      this.message = function() {
+        return "Expected the pass "
+             + (this.isNot ? "not " : "")
+             + "to change the AST " + jasmine.pp(ast) + " "
+             + "to match " + jasmine.pp(details) + ", "
+             + "but it " + (this.isNot ? "did" : "didn't") + ".";
+      };
+
+      return matchDetails(ast, details);
+    }
+  });
+});
diff --git a/spec/index.html b/spec/index.html
index 7622420..8f864a6 100644
--- a/spec/index.html
+++ b/spec/index.html
@@ -6,11 +6,13 @@
     <script src="vendor/jasmine/jasmine.js"></script>
     <script src="vendor/jasmine/jasmine-html.js"></script>
     <script src="../lib/peg.js"></script>
+    <script src="helpers.js"></script>
     <script src="parser.spec.js"></script>
     <script src="generated-parser.spec.js"></script>
     <script src="compiler/passes/report-missing-rules.spec.js"></script>
     <script src="compiler/passes/report-left-recursion.spec.js"></script>
     <script src="compiler/passes/compute-var-names.spec.js"></script>
+    <script src="compiler/passes/compute-params.spec.js"></script>
     <script>
       (function() {
         var env      = jasmine.getEnv(),
diff --git a/test/compiler/passes/compute-params-test.js b/test/compiler/passes/compute-params-test.js
deleted file mode 100644
index 2f02afe..0000000
--- a/test/compiler/passes/compute-params-test.js
+++ /dev/null
@@ -1,167 +0,0 @@
-(function() {
-
-module("PEG.compiler.passes.computeParams");
-
-test("computes params", function() {
-  function extractNode(node)       { return node; }
-  function extractExpression(node) { return node.expression; }
-
-  var cases = [
-    /* Bacics */
-    {
-      grammar:   'start = a:"a" { }',
-      extractor: extractNode,
-      params:    { a: "result0" }
-    },
-    {
-      grammar:   'start = a:"a" &{ }',
-      extractor: function(node) { return node.elements[1]; },
-      params:    { a: "result0" }
-    },
-    {
-      grammar:   'start = a:"a" !{ }',
-      extractor: function(node) { return node.elements[1]; },
-      params:    { a: "result0" }
-    },
-
-    /* Recursive walk */
-    {
-      grammar:   'start = a:"a" { } / "b" / "c"',
-      extractor: function(node) { return node.alternatives[0]; },
-      params:    { a: "result0" }
-    },
-    {
-      grammar:   'start = "a" / "b" / c:"c" { }',
-      extractor: function(node) { return node.alternatives[2]; },
-      params:    { c: "result0" }
-    },
-    {
-      grammar:   'start = (a:"a" { }) "b" "c"',
-      extractor: function(node) { return node.elements[0]; },
-      params:    { a: "result0" }
-    },
-    {
-      grammar:   'start = "a" "b" (c:"c" { })',
-      extractor: function(node) { return node.elements[2]; },
-      params:    { c: "result2" }
-    },
-    {
-      grammar:   'start = a:(b:"b" { })',
-      extractor: extractExpression,
-      params:    { b: "result0" }
-    },
-    {
-      grammar:   'start = &(a:"a" { })',
-      extractor: extractExpression,
-      params:    { a: "result0" }
-    },
-    {
-      grammar:   'start = !(a:"a" { })',
-      extractor: extractExpression,
-      params:    { a: "result0" }
-    },
-    {
-      grammar:   'start = (a:"a" { })?',
-      extractor: extractExpression,
-      params:    { a: "result0" }
-    },
-    {
-      grammar:   'start = (a:"a" { })*',
-      extractor: extractExpression,
-      params:    { a: "result1" }
-    },
-    {
-      grammar:   'start = (a:"a" { })+',
-      extractor: extractExpression,
-      params:    { a: "result1" }
-    },
-    {
-      grammar:   'start = (a:"a" { }) { }',
-      extractor: extractExpression,
-      params:    { a: "result0" }
-    },
-
-    /* Scoping */
-    {
-      grammar:   'start = (a:"a" / b:"b" / c:"c") { }',
-      extractor: extractNode,
-      params:    { }
-    },
-    {
-      grammar:   'start = a:(b:"b") { }',
-      extractor: extractNode,
-      params:    { a: "result0" }
-    },
-    {
-      grammar:   'start = &(a:"a") { }',
-      extractor: extractNode,
-      params:    { }
-    },
-    {
-      grammar:   'start = !(a:"a") { }',
-      extractor: extractNode,
-      params:    { }
-    },
-    {
-      grammar:   'start = (a:"a")? { }',
-      extractor: extractNode,
-      params:    { }
-    },
-    {
-      grammar:   'start = (a:"a")* { }',
-      extractor: extractNode,
-      params:    { }
-    },
-    {
-      grammar:   'start = (a:"a")+ { }',
-      extractor: extractNode,
-      params:    { }
-    },
-    {
-      grammar:   'start = (a:"a" { }) { }',
-      extractor: extractNode,
-      params:    { }
-    },
-
-    /* Sequences */
-    {
-      grammar:   'start = a:"a" b:"b" c:"c" { }',
-      extractor: extractNode,
-      params:    { a: "result0[0]", b: "result0[1]", c: "result0[2]" }
-    },
-    {
-      grammar:   'start = a:"a" (b:"b" c:"c" d:"d") e:"e"{ }',
-      extractor: extractNode,
-      params:    {
-        a: "result0[0]",
-        b: "result0[1][0]",
-        c: "result0[1][1]",
-        d: "result0[1][2]",
-        e: "result0[2]"
-      }
-    },
-    /*
-     * Regression tests for a bug where e.g. resultVar names like |result10|
-     * were incorrectly treated as names derived from |result1|, leading to
-     * incorrect substitution.
-     */
-    {
-      grammar:   'start = ("a" "b" "c" "d" "e" "f" "g" "h" "i" j:"j" { })*',
-      extractor: extractExpression,
-      params:    { j: "result1[9]" } // Buggy code put "result1[0]0" here.
-    }
-  ];
-
-  for (var i = 0; i < cases.length; i++) {
-    var ast = PEG.parser.parse(cases[i].grammar);
-    PEG.compiler.passes.computeVarNames(ast);
-    PEG.compiler.passes.computeParams(ast);
-
-    deepEqual(
-      cases[i].extractor(ast.rules[0].expression).params,
-      cases[i].params
-    );
-  }
-});
-
-})();
diff --git a/test/index.html b/test/index.html
index cad99a1..2ef31a3 100644
--- a/test/index.html
+++ b/test/index.html
@@ -8,7 +8,6 @@
     <script src="vendor/qunit/qunit.js"></script>
     <script src="helpers.js"></script>
     <script src="compiler/passes/remove-proxy-rules-test.js"></script>
-    <script src="compiler/passes/compute-params-test.js"></script>
   </head>
   <body>
     <h1 id="qunit-header">PEG.js Test Suite</h1>
diff --git a/test/run b/test/run
index 33685a6..e1732c7 100755
--- a/test/run
+++ b/test/run
@@ -75,8 +75,7 @@ QUnit.done(function(details) {
 
 [
   "helpers.js",
-  "compiler/passes/remove-proxy-rules-test.js",
-  "compiler/passes/compute-params-test.js"
+  "compiler/passes/remove-proxy-rules-test.js"
 ].forEach(function(file) {
   eval("with (QUnit) {" + fs.readFileSync(__dirname + "/" + file, "utf8") + "}");
 });