diff --git a/bin/compiler.php b/bin/compiler.php
index 365062ae..d3248409 100755
--- a/bin/compiler.php
+++ b/bin/compiler.php
@@ -3,6 +3,7 @@
 require __DIR__ . '/bootstrap.php';
 
 use PhpAot\Php\FileScanner;
+use PhpAot\Php\SyntaxError;
 use PhpAot\Php\Translator;
 use PhpAot\Php\Unsupported;
 
@@ -41,6 +42,8 @@ foreach ($list as $k => $file) {
             echo " unsupported syntax: " . $e->getMessage() . "\n";
             echo " skip: " . $file . "\n";
             unset($list[$k]);
+        } catch (SyntaxError $e) {
+            unset($list[$k]);
         }
     }
 }
diff --git a/src/Php/Preprocessor.php b/src/Php/Preprocessor.php
index d5a31070..92ea303c 100644
--- a/src/Php/Preprocessor.php
+++ b/src/Php/Preprocessor.php
@@ -85,7 +85,12 @@ class Preprocessor extends CompilerBase
         $phpCode = $this->loadFile($file);
 
         $this->climate->info('prepare: ' . $this->file);
-        $ast = $this->parser->parse($phpCode);
+        try {
+            $ast = $this->parser->parse($phpCode);
+        } catch (\PhpParser\Error $e) {
+            $this->climate->red("Fatal error: {$e->getMessage()} in {$this->file}");
+            throw new SyntaxError($e->getMessage(), $e->getCode());
+        }
 
         $traverser = new NodeTraverser();
         $traverser->addVisitor(new Visitor());
diff --git a/src/Php/SyntaxError.php b/src/Php/SyntaxError.php
new file mode 100644
index 00000000..689a8cb6
--- /dev/null
+++ b/src/Php/SyntaxError.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace PhpAot\Php;
+
+class SyntaxError extends \RuntimeException
+{
+
+}
\ No newline at end of file
diff --git a/src/Php/Translator.php b/src/Php/Translator.php
index 0bacbff6..e661983e 100644
--- a/src/Php/Translator.php
+++ b/src/Php/Translator.php
@@ -769,7 +769,11 @@ class Translator extends Preprocessor
         $flags = $v->flags;
         $type = $v->type ? $this->getTypeFromZendType($this->parseIdentifier($v->type)) : self::TYPE_VAR;
         foreach ($v->consts as $const) {
-            $constInfo = new ConstantDef($this->parseIdentifier($const->name), $flags, $type, $this->parseIdentifier($const->value));
+            $constName = $this->parseIdentifier($const->name);
+            if (isset($this->classDef->constants[$constName])) {
+                $this->fatalError($const, 'Cannot redefine class constant ' . $this->class . '::' . $constName);
+            }
+            $constInfo = new ConstantDef($constName, $flags, $type, $this->parseIdentifier($const->value));
             $this->classDef->constants[$constInfo->name] = $constInfo;
         }
     }
diff --git a/tests/core/classes/constants_error_001.phpt b/tests/core/classes/constants_error_001.phpt
new file mode 100644
index 00000000..13428675
--- /dev/null
+++ b/tests/core/classes/constants_error_001.phpt
@@ -0,0 +1,18 @@
+--TEST--
+Error case: duplicate class constant definition
+--SKIPIF--
+<?php die('skip, failed at compile time'); ?>
+--FILE--
+<?php
+  class myclass
+  {
+      const myConst = "hello";
+      const myConst = "hello again";
+  }
+
+function main() {
+
+}
+?>
+--EXPECTF--
+Fatal error: Cannot redefine class constant myclass::myConst in %s on line 5
diff --git a/tests/core/classes/constants_error_002.phpt b/tests/core/classes/constants_error_002.phpt
new file mode 100644
index 00000000..32aba740
--- /dev/null
+++ b/tests/core/classes/constants_error_002.phpt
@@ -0,0 +1,13 @@
+--TEST--
+Error case: class constant as an array
+--FILE--
+<?php
+  class myclass
+  {
+      const myConst = array();
+  }
+function main() {
+
+}
+?>
+--EXPECT--
diff --git a/tests/core/classes/constants_error_005.phpt b/tests/core/classes/constants_error_005.phpt
new file mode 100644
index 00000000..9c31e147
--- /dev/null
+++ b/tests/core/classes/constants_error_005.phpt
@@ -0,0 +1,16 @@
+--TEST--
+Error case: class constant as an encapsed containing a variable
+--SKIPIF--
+<?php die('skip, failed at compile time'); ?>
+--FILE--
+<?php
+  class myclass
+  {
+      const myConst = "$myVar";
+  }
+function main() {
+
+}
+?>
+--EXPECTF--
+Fatal error: Constant expression contains invalid operations in %s on line %d