diff --git a/scanner/lexer.go b/scanner/lexer.go
index 690a3a8..a2f322f 100644
--- a/scanner/lexer.go
+++ b/scanner/lexer.go
@@ -440,6 +440,7 @@ type Lexer struct {
 	StateStack    []int
 	PhpDocComment string
 	Comments      []comment.Comment
+	heredocLabel  []lex.Char
 }
 
 // Rune2Class returns the rune integer id
@@ -467,7 +468,7 @@ func NewLexer(src io.Reader, fName string) *Lexer {
 	if err != nil {
 		panic(err)
 	}
-	return &Lexer{lx, []int{0}, "", nil}
+	return &Lexer{lx, []int{0}, "", nil, nil}
 }
 
 func (l *Lexer) ungetChars(n int) []lex.Char {
diff --git a/scanner/scanner.go b/scanner/scanner.go
index fde9daf..0dd4568 100644
--- a/scanner/scanner.go
+++ b/scanner/scanner.go
@@ -29,8 +29,6 @@ const (
 	BACKQUOTE
 )
 
-var heredocLabel []lex.Char
-
 func isValidFirstVarNameRune(r rune) bool {
 	return r >= 'A' && r <= 'Z' || r == '_' || r >= 'a' && r <= 'z' || r >= '\u007f' && r <= 'ÿ'
 }
@@ -8494,19 +8492,19 @@ yyrule141: // [b]?\<\<\<[ \t]*({VAR_NAME}|([']{VAR_NAME}['])|(["]{VAR_NAME}["]))
 		default:
 			l.begin(HEREDOC)
 		}
-		heredocLabel = make([]lex.Char, lblLast-lblFirst+1)
-		copy(heredocLabel, tb[lblFirst:lblLast+1])
+		l.heredocLabel = make([]lex.Char, lblLast-lblFirst+1)
+		copy(l.heredocLabel, tb[lblFirst:lblLast+1])
 
-		ungetCnt := len(heredocLabel)
+		ungetCnt := len(l.heredocLabel)
 		searchLabelAhead := []lex.Char{}
-		for i := 0; i < len(heredocLabel); i++ {
+		for i := 0; i < len(l.heredocLabel); i++ {
 			if c == -1 {
 				break
 			}
 			searchLabelAhead = append(searchLabelAhead, l.Lookahead())
 			c = l.Next()
 		}
-		if bytes.Equal(l.charsToBytes(heredocLabel), l.charsToBytes(searchLabelAhead)) && ';' == rune(c) {
+		if bytes.Equal(l.charsToBytes(l.heredocLabel), l.charsToBytes(searchLabelAhead)) && ';' == rune(c) {
 			ungetCnt++
 			c = l.Next()
 			if '\n' == rune(c) || '\r' == rune(c) {
@@ -8528,14 +8526,14 @@ yyrule142: // .|[ \t\n\r]
 				break
 			}
 			if '\n' == rune(c) || '\r' == rune(c) {
-				if bytes.Equal(append(l.charsToBytes(heredocLabel), ';'), searchLabel) {
+				if bytes.Equal(append(l.charsToBytes(l.heredocLabel), ';'), searchLabel) {
 					l.begin(HEREDOC_END)
-					tb = l.ungetChars(len(heredocLabel) + 1)
+					tb = l.ungetChars(len(l.heredocLabel) + 1)
 					break
 				}
-				if bytes.Equal(l.charsToBytes(heredocLabel), searchLabel) {
+				if bytes.Equal(l.charsToBytes(l.heredocLabel), searchLabel) {
 					l.begin(HEREDOC_END)
-					tb = l.ungetChars(len(heredocLabel))
+					tb = l.ungetChars(len(l.heredocLabel))
 					break
 				}
 
@@ -8734,15 +8732,15 @@ yyrule152: // .|[ \t\n\r]
 				}
 				fallthrough
 			case '\n':
-				if bytes.Equal(append(l.charsToBytes(heredocLabel), ';'), searchLabel) {
+				if bytes.Equal(append(l.charsToBytes(l.heredocLabel), ';'), searchLabel) {
 					l.begin(HEREDOC_END)
-					tb = l.ungetChars(len(heredocLabel) + 1 + nls)
+					tb = l.ungetChars(len(l.heredocLabel) + 1 + nls)
 					lval.Token(l.newToken(tb))
 					return T_ENCAPSED_AND_WHITESPACE
 				}
-				if bytes.Equal(l.charsToBytes(heredocLabel), searchLabel) {
+				if bytes.Equal(l.charsToBytes(l.heredocLabel), searchLabel) {
 					l.begin(HEREDOC_END)
-					tb = l.ungetChars(len(heredocLabel) + nls)
+					tb = l.ungetChars(len(l.heredocLabel) + nls)
 					lval.Token(l.newToken(tb))
 					return T_ENCAPSED_AND_WHITESPACE
 				}
diff --git a/scanner/scanner.l b/scanner/scanner.l
index e3a105b..4b1db95 100644
--- a/scanner/scanner.l
+++ b/scanner/scanner.l
@@ -28,8 +28,6 @@ const (
 	BACKQUOTE
 )
 
-var heredocLabel []lex.Char
-
 func isValidFirstVarNameRune(r rune) bool {
     return r >= 'A' && r <= 'Z' || r == '_' || r >= 'a' && r <= 'z' || r >= '\u007f' && r <= 'ÿ'
 }
@@ -381,12 +379,12 @@ NEW_LINE        (\r|\n|\r\n)
             l.begin(HEREDOC)
     }
 
-    heredocLabel = make([]lex.Char, lblLast - lblFirst + 1)
-    copy(heredocLabel, tb[lblFirst:lblLast+1])
+    l.heredocLabel = make([]lex.Char, lblLast - lblFirst + 1)
+    copy(l.heredocLabel, tb[lblFirst:lblLast+1])
     
-    ungetCnt := len(heredocLabel)
+    ungetCnt := len(l.heredocLabel)
     searchLabelAhead := []lex.Char{}
-    for i := 0; i < len(heredocLabel); i++ {
+    for i := 0; i < len(l.heredocLabel); i++ {
         if c == -1 {
             break;
         }
@@ -394,7 +392,7 @@ NEW_LINE        (\r|\n|\r\n)
         c = l.Next()
     }
 
-    if bytes.Equal(l.charsToBytes(heredocLabel), l.charsToBytes(searchLabelAhead)) && ';' == rune(c) {
+    if bytes.Equal(l.charsToBytes(l.heredocLabel), l.charsToBytes(searchLabelAhead)) && ';' == rune(c) {
         ungetCnt++
         c = l.Next()
         if '\n' == rune(c) || '\r' == rune(c) {
@@ -417,15 +415,15 @@ NEW_LINE        (\r|\n|\r\n)
         }
 
         if '\n' == rune(c) || '\r' == rune(c) {
-            if bytes.Equal(append(l.charsToBytes(heredocLabel), ';'), searchLabel) {
+            if bytes.Equal(append(l.charsToBytes(l.heredocLabel), ';'), searchLabel) {
                 l.begin(HEREDOC_END)
-                tb = l.ungetChars(len(heredocLabel)+1)
+                tb = l.ungetChars(len(l.heredocLabel)+1)
                 break;
             }
 
-            if bytes.Equal(l.charsToBytes(heredocLabel), searchLabel) {
+            if bytes.Equal(l.charsToBytes(l.heredocLabel), searchLabel) {
                 l.begin(HEREDOC_END)
-                tb = l.ungetChars(len(heredocLabel))
+                tb = l.ungetChars(len(l.heredocLabel))
                 break;
             }
             
@@ -597,16 +595,16 @@ NEW_LINE        (\r|\n|\r\n)
                 fallthrough
 
             case '\n':
-                if bytes.Equal(append(l.charsToBytes(heredocLabel), ';'), searchLabel) { 
+                if bytes.Equal(append(l.charsToBytes(l.heredocLabel), ';'), searchLabel) { 
                     l.begin(HEREDOC_END)
-                    tb = l.ungetChars(len(heredocLabel)+1+nls)
+                    tb = l.ungetChars(len(l.heredocLabel)+1+nls)
                     lval.Token(l.newToken(tb)); 
                     return T_ENCAPSED_AND_WHITESPACE
                 }
 
-                if bytes.Equal(l.charsToBytes(heredocLabel), searchLabel) { 
+                if bytes.Equal(l.charsToBytes(l.heredocLabel), searchLabel) { 
                     l.begin(HEREDOC_END)
-                    tb = l.ungetChars(len(heredocLabel)+nls)
+                    tb = l.ungetChars(len(l.heredocLabel)+nls)
                     lval.Token(l.newToken(tb)); 
                     return T_ENCAPSED_AND_WHITESPACE
                 }