diff --git a/lib/syntax/parse.js b/lib/syntax/parse.js
index 5c1466a2..a9ebd753 100644
--- a/lib/syntax/parse.js
+++ b/lib/syntax/parse.js
@@ -20,6 +20,10 @@ function readWord(str, start) {
         end++;
     }
 
+    if (start === end) {
+        error(str, start, 'Expect a keyword');
+    }
+
     return str.substring(start, end);
 }
 
@@ -111,14 +115,12 @@ function readMultiplier(str, pos) {
 
             if (charAt(str, pos) === '{') {
                 var range = readMultiplierRange(str, pos);
-                if (range) {
-                    return {
-                        comma: true,
-                        min: range.min,
-                        max: range.max,
-                        value: str.substring(start, range.pos)
-                    };
-                }
+                return {
+                    comma: true,
+                    min: range.min,
+                    max: range.max,
+                    value: str.substring(start, range.pos)
+                };
             }
 
             return {
@@ -132,15 +134,12 @@ function readMultiplier(str, pos) {
             var start = pos;
             var range = readMultiplierRange(str, pos);
 
-            if (range) {
-                return {
-                    comma: false,
-                    min: range.min,
-                    max: range.max,
-                    value: str.substring(start, range.pos)
-                };
-            }
-            break;
+            return {
+                comma: false,
+                min: range.min,
+                max: range.max,
+                value: str.substring(start, range.pos)
+            };
     }
 
     return {
@@ -159,7 +158,7 @@ function readProperty(str, start) {
     end += eat(str, end, '<');
     end += eat(str, end, '\'');
 
-    name = readWord(str, end) || error(str, end);
+    name = readWord(str, end);
     end += name.length;
 
     end += eat(str, end, '\'');
@@ -185,7 +184,7 @@ function readType(str, start) {
 
     end += eat(str, end, '<');
 
-    name = readWord(str, end) || error(str, end);
+    name = readWord(str, end);
     end += name.length;
 
     if (charAt(str, end) === '(' && charAt(str, end + 1) === ')') {
@@ -214,7 +213,7 @@ function readKeywordOrFunction(str, start) {
     var multiplier;
     var name;
 
-    name = readWord(str, end) || error(str, end);
+    name = readWord(str, end);
     end += name.length;
 
     if (charAt(str, end) === '(') {
@@ -300,7 +299,7 @@ function readSequence(str, start) {
             if (token.type === 'Combinator') {
                 // check for combinator in group beginning and double combinator sequence
                 if (!lastToken || lastToken.type === 'Combinator') {
-                    error(str, end);
+                    error(str, end, 'Unexpected combinator');
                 }
 
                 combinators[token.value] = true;
@@ -321,7 +320,7 @@ function readSequence(str, start) {
 
     // check for combinator in group ending
     if (lastToken && lastToken.type === 'Combinator') {
-        error(str, end - lastToken.value.length);
+        error(str, end - lastToken.value.length, 'Unexpected combinator');
     }
 
     return {
@@ -409,13 +408,12 @@ function peek(str, start) {
             };
 
         case '&':
-            if (charAt(str, end) === '&') {
-                return {
-                    type: 'Combinator',
-                    value: '&&'
-                };
-            }
-            break;
+            eat(str, end, '&');
+
+            return {
+                type: 'Combinator',
+                value: '&&'
+            };
 
         case ',':
             return {
diff --git a/test/syntax.js b/test/syntax.js
index 29f9dd6d..6cec3301 100755
--- a/test/syntax.js
+++ b/test/syntax.js
@@ -55,6 +55,73 @@ describe('CSS syntax', function() {
         assert.equal(stringify(ast, true), '[ [ a b ] | [ c || [ d && [ e f ] ] ] ]');
     });
 
+    describe('bad syntax', function() {
+        it('expected a quote', function() {
+            assert.throws(function() {
+                parse('\'x');
+            }, /^SyntaxParseError: Expect a quote\n/);
+        });
+
+        it('expected a number', function() {
+            var tests = [
+                '<x>{}',
+                '<x>{,2}',
+                '<x>{ 2}',
+                '<x>{1, }'
+            ];
+            tests.forEach(function(test) {
+                assert.throws(function() {
+                    parse(test);
+                }, /^SyntaxParseError: Expect a number\n/, test);
+            });
+        });
+
+        it('missed keyword', function() {
+            var tests = [
+                '<>',
+                '<\'\'>'
+            ];
+            tests.forEach(function(test) {
+                assert.throws(function() {
+                    parse(test);
+                }, /^SyntaxParseError: Expect a keyword\n/, test);
+            });
+        });
+
+        it('unexpected combinator', function() {
+            var tests = [
+                '<x>&&',
+                '&&<x>',
+                '<x>&&||'
+            ];
+            tests.forEach(function(test) {
+                assert.throws(function() {
+                    parse(test);
+                }, /^SyntaxParseError: Unexpected combinator\n/, test);
+            });
+        });
+
+        it('unexpected input', function() {
+            assert.throws(function() {
+                parse('!');
+            }, /^SyntaxParseError: Unexpected input\n/);
+        });
+
+        it('bad syntax', function() {
+            var tests = [
+                'a&b',
+                '<a',
+                'b(',
+                '[a'
+            ];
+            tests.forEach(function(test) {
+                assert.throws(function() {
+                    parse(test);
+                }, /^SyntaxParseError: Expect `.`\n/, test);
+            });
+        });
+    });
+
     describe('Syntax', function() {
         it('validate', function() {
             var syntax = createSyntax({