diff --git a/src/Compiler/CompileUtil.php b/src/Compiler/CompileUtil.php
index e9eccd6..8ff4362 100644
--- a/src/Compiler/CompileUtil.php
+++ b/src/Compiler/CompileUtil.php
@@ -2,6 +2,10 @@
 
 namespace PhpPkg\EasyTpl\Compiler;
 
+use function defined;
+use function str_contains;
+use function str_starts_with;
+
 /**
  * class CompileUtil
  *
@@ -26,7 +30,22 @@ class CompileUtil
      */
     public static function canAddVarPrefix(string $line): bool
     {
-        return $line[0] !== '$' && preg_match(self::REGEX_VAR_NAME, $line) === 1;
+        // has prefix or is magic const. (eg: __LINE__)
+        if ($line[0] === '$' || str_starts_with($line, '__')) {
+            return false;
+        }
+
+        if (preg_match(self::REGEX_VAR_NAME, $line) === 1) {
+            if (str_contains($line, '.') || str_contains($line, '-')) {
+                return true;
+            }
+
+            // up: check is const name
+            // - defined() cannot check magic const. (eg: __LINE__)
+            return !defined($line);
+        }
+
+        return false;
     }
 
     /**
diff --git a/test/Compiler/CompileUtilTest.php b/test/Compiler/CompileUtilTest.php
index 90d085f..10da2c5 100644
--- a/test/Compiler/CompileUtilTest.php
+++ b/test/Compiler/CompileUtilTest.php
@@ -21,6 +21,8 @@ public function testCanAddVarPrefix(): void
 
         $this->assertFalse(CompileUtil::canAddVarPrefix("top['abc']"));
         $this->assertFalse(CompileUtil::canAddVarPrefix('abc()'));
+        $this->assertFalse(CompileUtil::canAddVarPrefix('PHP_OS'));
+        $this->assertFalse(CompileUtil::canAddVarPrefix('__LINE__'));
     }
 
     public function testPathToArrayAccess(): void
diff --git a/test/Compiler/PregCompilerTest.php b/test/Compiler/PregCompilerTest.php
index 12320fd..36c8878 100644
--- a/test/Compiler/PregCompilerTest.php
+++ b/test/Compiler/PregCompilerTest.php
@@ -63,7 +63,7 @@ public function testToken_getBlockNamePattern():void
         ];
 
         $pattern = Token::getBlockNamePattern();
-        vdump($pattern);
+        // vdump($pattern);
         foreach ($tests as [$in, $out]) {
             $ret = preg_match($pattern, $in, $matches);
             if ($out) {
@@ -79,10 +79,27 @@ public function testCompileCode_inline_echo():void
     {
         $p = new PregCompiler();
 
+        $this->assertNotEquals('<?= $name ?>', $p->compile('{{= name }}'));
+
         $tests = [
             ['{{ "a" . "b" }}', '<?= "a" . "b" ?>'],
+            // const
+            ['{{ PHP_OS }}', '<?= PHP_OS ?>'],
+            ['{{= PHP_OS }}', '<?= PHP_OS ?>'],
+            ["{{\n PHP_OS }}", "<?= PHP_OS ?>"],
+            ['{{ echo PHP_OS }}', '<?php echo PHP_OS ?>'],
+            ['{{ __LINE__ }}', '<?= __LINE__ ?>'],
+            ['{{= __LINE__ }}', '<?= __LINE__ ?>'],
+            ['{{ echo __LINE__ }}', '<?php echo __LINE__ ?>'],
+            ['{{ SomeClass::NAME }}', '<?= SomeClass::NAME ?>'],
+            ['{{ echo SomeClass::NAME }}', '<?= SomeClass::NAME ?>'],
+            // prop
+            ['{{ SomeClass::$name }}', '<?= SomeClass::$name ?>'],
+            // var
             ['{{ name }}', '<?= $name ?>'],
             ['{{ $name }}', '<?= $name ?>'],
+            ['{{= $name }}', '<?= $name ?>'],
+            ['{{ echo $name }}', '<?php echo $name ?>'],
             ['{{ $name; }}', '<?= $name; ?>'],
             ['{{ $name ?: "inhere" }}', '<?= $name ?: "inhere" ?>'],
             ['{{ $name ?? "inhere" }}', '<?= $name ?? "inhere" ?>'],
@@ -104,37 +121,21 @@ public function testCompileCode_inline_echo():void
             // func
             ['{{ some_func() }}', '<?= some_func() ?>'],
             ['{{ some_func(); }}', '<?= some_func(); ?>'],
+            ['{{ SomeClass::func(); }}', '<?= SomeClass::func(); ?>'],
             ['{{ $this->include("header.tpl") }}', '<?= $this->include("header.tpl") ?>'],
+            // more
+            [
+                '{{= $ctx.pkgName ?? "org.example.entity" }}',
+                '<?= $ctx[\'pkgName\'] ?? "org.example.entity" ?>'
+            ],
+            [
+                '{{= $ctx->pkgName ?? "org.example.entity" }}',
+                '<?= $ctx->pkgName ?? "org.example.entity" ?>'
+            ],
         ];
         foreach ($tests as [$in, $out]) {
             $this->assertEquals($out, $p->compile($in));
         }
-
-        $tplCode = <<<'TPL'
-
-{{= $ctx.pkgName ?? "org.example.entity" }}
-
-TPL;
-        $compiled = $p->compile($tplCode);
-        // vdump($tplCode, $compiled);
-        $this->assertNotEmpty($compiled);
-        $this->assertEquals(<<<'CODE'
-
-<?= $ctx['pkgName'] ?? "org.example.entity" ?>
-
-CODE
-            ,$compiled);
-
-        $tplCode = <<<'TPL'
-{{= $ctx->pkgName ?? "org.example.entity" }}
-TPL;
-        $compiled = $p->compile($tplCode);
-        // vdump($tplCode, $compiled);
-        $this->assertNotEmpty($compiled);
-        $this->assertEquals(<<<'CODE'
-<?= $ctx->pkgName ?? "org.example.entity" ?>
-CODE
-            ,$compiled);
     }
 
     public function testCompile_inline_echo_with_filters():void
@@ -182,6 +183,38 @@ public function testCompile_disableEchoFilter():void
         }
     }
 
+    public function testCompile_ml_define():void
+    {
+        $p = new PregCompiler();
+
+        $code = <<<'CODE'
+{{
+
+$a = random_int(1, 10);
+}}
+CODE;
+        $compiled = $p->compile($code);
+        $this->assertEquals(<<<'CODE'
+<?php $a = random_int(1, 10); ?>
+CODE
+            ,$compiled);
+
+        $code = <<<'CODE'
+{{
+// comments
+$a = random_int(1, 10);
+}}
+CODE;
+        $compiled = $p->compile($code);
+        $this->assertEquals(<<<'CODE'
+<?php
+// comments
+$a = random_int(1, 10);
+?>
+CODE
+            ,$compiled);
+    }
+
     public function testCompile_comments():void
     {
         $p = new PregCompiler();
@@ -274,38 +307,6 @@ public function testCompile_foreach():void
             ,$compiled);
     }
 
-    public function testCompile_ml_define():void
-    {
-        $p = new PregCompiler();
-
-        $code = <<<'CODE'
-{{
-
-$a = random_int(1, 10);
-}}
-CODE;
-        $compiled = $p->compile($code);
-        $this->assertEquals(<<<'CODE'
-<?php $a = random_int(1, 10); ?>
-CODE
-            ,$compiled);
-
-        $code = <<<'CODE'
-{{
-// comments
-$a = random_int(1, 10);
-}}
-CODE;
-        $compiled = $p->compile($code);
-        $this->assertEquals(<<<'CODE'
-<?php
-// comments
-$a = random_int(1, 10);
-?>
-CODE
-            ,$compiled);
-    }
-
     public function testCompile_customDirective_include():void
     {
         $p = new PregCompiler();