diff --git a/src/main/antlr/annis/AqlLexer.g4 b/src/main/antlr/annis/AqlLexer.g4
index 5b9da30..8fda46b 100644
--- a/src/main/antlr/annis/AqlLexer.g4
+++ b/src/main/antlr/annis/AqlLexer.g4
@@ -80,8 +80,12 @@
 fragment RE_star     : (RE_char | RE_chgroup | ( '(' REGEX ')')) '*';
 fragment RE_plus     : (RE_char | RE_chgroup | ( '(' REGEX ')')) '+';
 fragment RE_occ      : (RE_char | RE_chgroup | ( '(' REGEX ')')) FOCC;
+fragment RE_expr     : '.' | RE_char | RE_alter | RE_chgroup | RE_opt | RE_quant;
+fragment RE_orgroup  : '(' RE_expr* ('|' RE_expr+ )* ')' ;
 fragment RE_group    : '(' REGEX ')';
-REGEX     		     : SLASH ('.' | RE_char | RE_alter | RE_chgroup | RE_opt | RE_quant | RE_group)* SLASH;
+//REGEX     		     : SLASH ('.' | RE_char | RE_alter | RE_chgroup | RE_opt | RE_quant | RE_group)* SLASH;
+
+REGEX     		     : SLASH (RE_expr | RE_group | RE_orgroup)* SLASH;
 
 
 WS : ( ' ' | '\t' | '\r' | '\n' )+ -> skip ;
diff --git a/src/main/antlr/annis/AqlParser.g4 b/src/main/antlr/annis/AqlParser.g4
index f26eb9b..5718a77 100644
--- a/src/main/antlr/annis/AqlParser.g4
+++ b/src/main/antlr/annis/AqlParser.g4
@@ -191,5 +191,5 @@
 
 
 exprTop
-: andTopExpr (OR andTopExpr)* # OrTop
+: BRACE_OPEN? andTopExpr (OR andTopExpr)* BRACE_CLOSE? # OrTop
 ;
\ No newline at end of file
diff --git a/src/test/java/de/ids_mannheim/korap/query/test/annis/BooleanGroupTest.java b/src/test/java/de/ids_mannheim/korap/query/test/annis/BooleanGroupTest.java
new file mode 100644
index 0000000..3fe8408
--- /dev/null
+++ b/src/test/java/de/ids_mannheim/korap/query/test/annis/BooleanGroupTest.java
@@ -0,0 +1,134 @@
+package de.ids_mannheim.korap.query.test.annis;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import de.ids_mannheim.korap.query.serialize.QuerySerializer;
+
+public class BooleanGroupTest {
+
+    private QuerySerializer qs = new QuerySerializer();
+    private ObjectMapper mapper = new ObjectMapper();
+    
+    private JsonNode runQuery (String query)
+            throws JsonProcessingException, JsonMappingException {
+        qs.setQuery(query, "annis");
+        JsonNode result = mapper.readTree(qs.toJSON());
+//        System.out.println(result.toPrettyString());  
+        return result;
+    }
+    
+    
+    @Test
+    public void testEmptyGroup () throws Exception {
+        JsonNode n = runQuery("/()/");
+        assertEquals("koral:token", n.at("/query/@type").asText());
+        assertEquals("koral:term", n.at("/query/wrap/@type").asText());
+        assertEquals("match:eq", n.at("/query/wrap/match").asText());
+        assertEquals("type:regex", n.at("/query/wrap/type").asText());
+        assertEquals("orth", n.at("/query/wrap/layer").asText());
+        assertEquals("()", n.at("/query/wrap/key").asText());
+    }
+    
+    @Test
+    public void testGroupInRegex () throws Exception {
+        JsonNode n = runQuery("/(Kat.*)/");
+        assertEquals("koral:token", n.at("/query/@type").asText());
+        assertEquals("koral:term", n.at("/query/wrap/@type").asText());
+        assertEquals("match:eq", n.at("/query/wrap/match").asText());
+        assertEquals("type:regex", n.at("/query/wrap/type").asText());
+        assertEquals("orth", n.at("/query/wrap/layer").asText());
+        assertEquals("(Kat.*)", n.at("/query/wrap/key").asText());
+    }
+
+    @Test
+    public void testOrGroup () throws Exception {
+        JsonNode n = runQuery("(cat=\"S\" | cat=\"NP\")");
+        assertEquals("koral:group", n.at("/query/@type").asText());
+        assertEquals("operation:disjunction", n.at("/query/operation").asText());
+        assertEquals("koral:span", n.at("/query/operands/0/@type").asText());
+        assertEquals("koral:term", n.at("/query/operands/0/wrap/@type").asText());
+        assertEquals("match:eq", n.at("/query/operands/0/wrap/match").asText());
+        assertEquals("c", n.at("/query/operands/0/wrap/layer").asText());
+        assertEquals("S", n.at("/query/operands/0/wrap/key").asText());
+        assertEquals("c", n.at("/query/operands/1/wrap/layer").asText());
+        assertEquals("NP", n.at("/query/operands/1/wrap/key").asText());
+    }
+    
+    @Test
+    public void testOrGroupRegex () throws Exception {
+        JsonNode n = runQuery("/(be|have)/");
+        assertEquals("koral:token", n.at("/query/@type").asText());
+        assertEquals("koral:term", n.at("/query/wrap/@type").asText());
+        assertEquals("match:eq", n.at("/query/wrap/match").asText());
+        assertEquals("type:regex", n.at("/query/wrap/type").asText());
+        assertEquals("orth", n.at("/query/wrap/layer").asText());
+        assertEquals("(be|have)", n.at("/query/wrap/key").asText());
+    }
+    
+    @Test
+    public void testLemmaOrGroupRegex () throws Exception {
+        JsonNode n = runQuery("lemma=/(be|have)/");
+        assertEquals("koral:token", n.at("/query/@type").asText());
+        assertEquals("koral:term", n.at("/query/wrap/@type").asText());
+        assertEquals("match:eq", n.at("/query/wrap/match").asText());
+        assertEquals("type:regex", n.at("/query/wrap/type").asText());
+        assertEquals("l", n.at("/query/wrap/layer").asText());
+        assertEquals("(be|have)", n.at("/query/wrap/key").asText());
+    }
+
+    
+    @Test
+    public void testAndGroup () throws Exception {
+        runQuery("tok=\"Katze\" & pos=\"N\"");
+        
+        // EM: Not sure how the expected result is
+        // Koral generates KQ only for the last operand:
+        /*
+         {
+          "query" : {
+            "@type" : "koral:token",
+            "wrap" : {
+              "@type" : "koral:term",
+              "match" : "match:eq",
+              "layer" : "p",
+              "key" : "N"
+            }
+          },
+          "@context" : "http://korap.ids-mannheim.de/ns/koral/0.3/context.jsonld"
+        }
+        */
+    }
+    
+    @Test
+    public void testRegexInGroup () throws Exception {
+        JsonNode n = runQuery("(/Kat.*/)");
+        
+        assertEquals("koral:token", n.at("/query/@type").asText());
+        assertEquals("koral:term", n.at("/query/wrap/@type").asText());
+        assertEquals("match:eq", n.at("/query/wrap/match").asText());
+        assertEquals("type:regex", n.at("/query/wrap/type").asText());
+        assertEquals("orth", n.at("/query/wrap/layer").asText());
+        assertEquals("Kat.*", n.at("/query/wrap/key").asText());
+    }
+    
+    @Test
+    public void testNestedGroupRegex () throws Exception {
+        JsonNode n =runQuery("(/(/Kat.*/)/)");
+        assertEquals("koral:token", n.at("/query/@type").asText());
+        assertEquals("koral:term", n.at("/query/wrap/@type").asText());
+        assertEquals("match:eq", n.at("/query/wrap/match").asText());
+        assertEquals("type:regex", n.at("/query/wrap/type").asText());
+        assertEquals("orth", n.at("/query/wrap/layer").asText());
+        assertEquals("(Kat.*)", n.at("/query/wrap/key").asText());
+        
+        // EM: I think the nested slashes are not necessary here 
+        // Please see fragment RE_group rule in AqlLexer.g4 #85
+    }
+}