diff --git a/src/main/antlr/poliqarpplus/PoliqarpPlusLexer.g4 b/src/main/antlr/poliqarpplus/PoliqarpPlusLexer.g4
index 8648d87..b3bedb1 100644
--- a/src/main/antlr/poliqarpplus/PoliqarpPlusLexer.g4
+++ b/src/main/antlr/poliqarpplus/PoliqarpPlusLexer.g4
@@ -86,9 +86,13 @@
 EMPTYREL	: '@';
 
 /* Regular expressions and Regex queries */
-fragment RE_char     : ~('*' | '?' | '+' | '{' | '}' | '[' | ']'
-                     | '(' | ')' | '|' | '"' | ':' | '\'' | '\\');
+fragment RE_symbol     : ~('*' | '?' | '+' | '{' | '}' | '[' | ']'
+                     | '(' | ')' | '|' | '\\' | '"' | ':' | '\'');
+fragment RE_esc      : '\\' ('.' | '*' | '?' | '+' | '{' | '}' | '[' | ']'
+                     | '(' | ')' | '|' | '\\' | '"' | ':' | '\'');
+fragment RE_char     : (RE_symbol | RE_esc );
 fragment RE_alter    : ((RE_char | ('(' RE_expr ')') | RE_chgroup) '|' RE_expr )+;
+
 fragment RE_chgroup  : '[' RE_char+ ']';
 fragment RE_quant	 : (RE_star | RE_plus | RE_occ) QMARK?;
 fragment RE_opt      : (RE_char | RE_chgroup | ( '(' RE_expr ')')) '?';
diff --git a/src/main/antlr/poliqarpplus/PoliqarpPlusParser.g4 b/src/main/antlr/poliqarpplus/PoliqarpPlusParser.g4
index 1907773..571cf12 100644
--- a/src/main/antlr/poliqarpplus/PoliqarpPlusParser.g4
+++ b/src/main/antlr/poliqarpplus/PoliqarpPlusParser.g4
@@ -43,9 +43,9 @@
 ;
 
 key
-: WORD
+: (WORD
 | regex
-| NUMBER
+| NUMBER)
 ;
 
 foundry
@@ -149,7 +149,7 @@
 ;
 
 alignment
-: segment? (CARET segment)* CARET?
+: segment? ( (CARET segment)+ | CARET)
 ;
 
 disjunction
diff --git a/src/test/java/de/ids_mannheim/korap/query/serialize/PoliqarpPlusQueryProcessorTest.java b/src/test/java/de/ids_mannheim/korap/query/serialize/PoliqarpPlusQueryProcessorTest.java
index 2cb60e3..520d9a4 100644
--- a/src/test/java/de/ids_mannheim/korap/query/serialize/PoliqarpPlusQueryProcessorTest.java
+++ b/src/test/java/de/ids_mannheim/korap/query/serialize/PoliqarpPlusQueryProcessorTest.java
@@ -155,18 +155,42 @@
         assertEquals("type:regex", res.at("/query/wrap/type").asText());
         assertEquals("orth", res.at("/query/wrap/layer").asText());
         assertEquals("match:eq", res.at("/query/wrap/match").asText());
+    }
 
+    @Test
+    public void testRegexEscape () throws JsonProcessingException, IOException {
         // Escape regex symbols
+        query = "\"a.+?\"";
+        qs.setQuery(query, "poliqarpplus");
+        res = mapper.readTree(qs.toJSON());
+        assertEquals("koral:token", res.at("/query/@type").asText());
+        assertEquals("koral:term", res.at("/query/wrap/@type").asText());
+        assertEquals("type:regex", res.at("/query/wrap/type").asText());
+        assertEquals("orth", res.at("/query/wrap/layer").asText());
+        assertEquals("match:eq", res.at("/query/wrap/match").asText());
+        assertEquals("a.+?", res.at("/query/wrap/key").asText());
+
         query = "\"a\\.\"";
         qs.setQuery(query, "poliqarpplus");
         res = mapper.readTree(qs.toJSON());
-        System.out.println("QUERY IS  " + res);
         assertEquals("koral:token", res.at("/query/@type").asText());
         assertEquals("koral:term", res.at("/query/wrap/@type").asText());
         assertEquals("type:regex", res.at("/query/wrap/type").asText());
         assertEquals("orth", res.at("/query/wrap/layer").asText());
         assertEquals("match:eq", res.at("/query/wrap/match").asText());
         assertEquals("a\\.", res.at("/query/wrap/key").asText());
+
+
+        query = "\"a\\.\\+\\?\\\\\"";
+        qs.setQuery(query, "poliqarpplus");
+        res = mapper.readTree(qs.toJSON());
+        assertEquals("koral:token", res.at("/query/@type").asText());
+        assertEquals("koral:term", res.at("/query/wrap/@type").asText());
+        assertEquals("type:regex", res.at("/query/wrap/type").asText());
+        assertEquals("orth", res.at("/query/wrap/layer").asText());
+        assertEquals("match:eq", res.at("/query/wrap/match").asText());
+        assertEquals("a\\.\\+\\?\\\\", res.at("/query/wrap/key").asText());
+
     }