diff --git a/org.eclipse.xtext.tests/src/org/eclipse/xtext/xtext/generator/hoisting/HoistingProcessorTest.java b/org.eclipse.xtext.tests/src/org/eclipse/xtext/xtext/generator/hoisting/HoistingProcessorTest.java
index 341f095ae..835348fb1 100644
--- a/org.eclipse.xtext.tests/src/org/eclipse/xtext/xtext/generator/hoisting/HoistingProcessorTest.java
+++ b/org.eclipse.xtext.tests/src/org/eclipse/xtext/xtext/generator/hoisting/HoistingProcessorTest.java
@@ -287,6 +287,23 @@ public class HoistingProcessorTest extends AbstractXtextTests {
 		Grammar grammar = ((Grammar) resource.getContents().get(0));
 		AbstractRule rule = getRule(grammar, "S");
 		
+		HoistingGuard guard = hoistingProcessor.findHoistingGuard(rule.getAlternatives());
+		assertFalse(guard.isTrivial());
+		assertTrue(guard.hasTerminal());
+		assertEquals("((" + getSyntaxForKeywordToken("a", 1) + " || (p0)) && (" + getSyntaxForKeywordToken("b", 1) + " || (p1)))", guard.render());
+	}
+	
+	//@Test
+	public void testUnorderedGroupsWithoutMandatoryContent() throws Exception {
+		// @formatter:off
+		String model =
+			MODEL_PREAMBLE +
+			"S: (($$ p0 $$?=> 'a')? & ($$ p1 $$?=> 'b')?) $$ p2 $$?=> 's';";
+		// @formatter:off
+		XtextResource resource = getResourceFromString(model);
+		Grammar grammar = ((Grammar) resource.getContents().get(0));
+		AbstractRule rule = getRule(grammar, "S");
+		
 		HoistingGuard guard = hoistingProcessor.findHoistingGuard(rule.getAlternatives());
 		assertFalse(guard.isTrivial());
 		assertTrue(guard.hasTerminal());
@@ -307,7 +324,7 @@ public class HoistingProcessorTest extends AbstractXtextTests {
 		HoistingGuard guard = hoistingProcessor.findHoistingGuard(rule.getAlternatives());
 		assertFalse(guard.isTrivial());
 		assertTrue(guard.hasTerminal());
-		assertEquals("((" + getSyntaxForKeywordToken("s", 1) + " || (p2)) && (" + getSyntaxForKeywordToken("a", 1) + " || (p0)) && (" + getSyntaxForKeywordToken("b", 1) + " || (p1)))", guard.render());
+		assertEquals("((" + getSyntaxForKeywordToken("a", 1) + " || (p0)) && (" + getSyntaxForKeywordToken("b", 1) + " || (p1)))", guard.render());
 		
 		// check sizes of groups in unordered group
 		Group group = (Group) rule.getAlternatives();
diff --git a/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/hoisting/HoistingProcessor.java b/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/hoisting/HoistingProcessor.java
index 594d5918d..4aa85c17a 100644
--- a/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/hoisting/HoistingProcessor.java
+++ b/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/hoisting/HoistingProcessor.java
@@ -25,6 +25,7 @@ import org.eclipse.xtext.Action;
 import org.eclipse.xtext.Alternatives;
 import org.eclipse.xtext.Assignment;
 import org.eclipse.xtext.CompoundElement;
+import org.eclipse.xtext.GrammarUtil;
 import org.eclipse.xtext.Group;
 import org.eclipse.xtext.JavaAction;
 import org.eclipse.xtext.RuleCall;
@@ -152,7 +153,12 @@ public class HoistingProcessor {
 				
 				Alternatives virtualAlternatives = XtextFactory.eINSTANCE.createAlternatives();
 				addElementsToCompoundElement(virtualAlternatives, ((UnorderedGroup) element).getElements());
-				virtualAlternatives.setCardinality("*");
+				if (((UnorderedGroup) element).getElements().stream().allMatch(GrammarUtil::isOptionalCardinality)) {
+					virtualAlternatives.setCardinality("*");
+					// TODO: alternatives analysis needs special case
+				} else {
+					virtualAlternatives.setCardinality("+");
+				}
 				
 				elements.set(i, virtualAlternatives);
 			}