diff --git a/pom.xml b/pom.xml
index e4cdd1a..cde601d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -64,7 +64,7 @@
 		<dependency>
 			<groupId>org.antlr</groupId>
 			<artifactId>antlr4-maven-plugin</artifactId>
-			<version>4.2</version>
+			<version>4.8-1</version>
 		</dependency>
 		<dependency>
 			<groupId>org.antlr</groupId>
diff --git a/src/main/antlr/poliqarpplus/PoliqarpPlusLexer.g4 b/src/main/antlr/poliqarpplus/PoliqarpPlusLexer.g4
index 81dbec7..02d1ffd 100644
--- a/src/main/antlr/poliqarpplus/PoliqarpPlusLexer.g4
+++ b/src/main/antlr/poliqarpplus/PoliqarpPlusLexer.g4
@@ -56,7 +56,7 @@
 /** Simple strings and Simple queries */
 WS                  : [ \t]  -> channel(HIDDEN);
 fragment FOCC       : '{' WS* ( [0-9]* WS* ',' WS* [0-9]+ | [0-9]+ WS* ','? ) WS* '}';
-fragment NO_RE      : ~[ \t\/];
+fragment NO_RE      : ~[ \t/];
 fragment ALPHABET   : ~('\t' | ' ' | '/' | '*' | '?' | '+' | '{' | '}' | '[' | ']'
                     | '(' | ')' | '|' | '"' | ',' | ':' | '\'' | '\\' | '!' | '=' | '~' | '&' | '^' | '<' | '>' );
 NUMBER              : [0-9]+;