diff --git a/spec/api/generated-parser-api.spec.js b/spec/api/generated-parser-api.spec.js
new file mode 100644
index 0000000..ad9ff24
--- /dev/null
+++ b/spec/api/generated-parser-api.spec.js
@@ -0,0 +1,50 @@
+describe("generated parser API", function() {
+  describe("parse", function() {
+    it("parses input", function() {
+      var parser = PEG.buildParser('start = "a"');
+
+      expect(parser.parse("a")).toBe("a");
+    });
+
+    it("throws an exception on syntax error", function() {
+      var parser = PEG.buildParser('start = "a"');
+
+      expect(function() { parser.parse("b"); }).toThrow();
+    });
+
+    describe("start rule", function() {
+      var parser = PEG.buildParser([
+            'a = "x" { return "a"; }',
+            'b = "x" { return "b"; }',
+            'c = "x" { return "c"; }'
+          ].join("\n"), { allowedStartRules: ["b", "c"] });
+
+      describe("when |startRule| is not set", function() {
+        it("starts parsing from the first allowed rule", function() {
+          expect(parser.parse("x")).toBe("b");
+        });
+      });
+
+      describe("when |startRule| is set to an allowed rule", function() {
+        it("starts parsing from the specified rule", function() {
+          expect(parser.parse("x", { startRule: "b" })).toBe("b");
+          expect(parser.parse("x", { startRule: "c" })).toBe("c");
+        });
+      });
+
+      describe("when |startRule| is set to a disallowed start rule", function() {
+        it("throws an exception", function() {
+          expect(
+            function() { parser.parse("x", { startRule: "a" }); }
+          ).toThrow();
+        });
+      });
+    });
+
+    it("accepts custom options", function() {
+      var parser = PEG.buildParser('start = "a"');
+
+      parser.parse("a", { foo: 42 });
+    });
+  });
+});
diff --git a/spec/api/generated-parser.spec.js b/spec/api/generated-parser-behavior.spec.js
similarity index 97%
rename from spec/api/generated-parser.spec.js
rename to spec/api/generated-parser-behavior.spec.js
index 252b0e1..1a809bc 100644
--- a/spec/api/generated-parser.spec.js
+++ b/spec/api/generated-parser-behavior.spec.js
@@ -1,4 +1,4 @@
-describe("generated parser", function() {
+describe("generated parser behavior", function() {
   function varyOptimizationOptions(block) {
     function clone(object) {
       var result = {}, key;
@@ -121,37 +121,6 @@ describe("generated parser", function() {
     });
   });
 
-  describe("parse", function() {
-    var parser = PEG.buildParser([
-          'a = "x" { return "a"; }',
-          'b = "x" { return "b"; }',
-          'c = "x" { return "c"; }'
-        ].join("\n"), { allowedStartRules: ["b", "c"] });
-
-    describe("start rule", function() {
-      describe("without the |startRule| option", function() {
-        it("uses the first allowed rule", function() {
-          expect(parser).toParse("x", "b");
-        });
-      });
-
-      describe("when the |startRule| option specifies allowed rule", function() {
-        it("uses the specified rule", function() {
-          expect(parser).toParse("x", { startRule: "b" }, "b");
-          expect(parser).toParse("x", { startRule: "c" }, "c");
-        });
-      });
-
-      describe("when the |startRule| option specifies disallowed rule", function() {
-        it("throws exception", function() {
-          expect(parser).toFailToParse("x", { startRule: "a" }, {
-            message: "Can't start parsing from rule \"a\"."
-          });
-        });
-      });
-    });
-  });
-
   varyOptimizationOptions(function(options) {
     describe("initializer code", function() {
       it("runs before the parsing begins", function() {
diff --git a/spec/index.html b/spec/index.html
index bd0d668..176f368 100644
--- a/spec/index.html
+++ b/spec/index.html
@@ -15,7 +15,8 @@
     <script src="unit/compiler/passes/generate-bytecode.spec.js"></script>
     <script src="api/pegjs-api.spec.js"></script>
     <script src="api/plugin-api.spec.js"></script>
-    <script src="api/generated-parser.spec.js"></script>
+    <script src="api/generated-parser-api.spec.js"></script>
+    <script src="api/generated-parser-behavior.spec.js"></script>
     <script>
       (function() {
         var env      = jasmine.getEnv(),