diff --git a/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java b/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java
index 928af5c..69c4452 100644
--- a/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java
+++ b/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java
@@ -18,17 +18,16 @@
 
 import java.io.IOException;
 import java.util.ListIterator;
-
 import org.junit.Test;
-import org.onosproject.yangutils.datamodel.YangNode;
-import org.onosproject.yangutils.datamodel.YangNodeType;
-import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
 import org.onosproject.yangutils.datamodel.YangLeaf;
 import org.onosproject.yangutils.datamodel.YangLeafList;
-import org.onosproject.yangutils.datamodel.YangDataTypes;
-import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
 import org.onosproject.yangutils.datamodel.YangPatternRestriction;
 import org.onosproject.yangutils.datamodel.YangStringRestriction;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
 
@@ -194,4 +193,12 @@
                 .getPatternList().listIterator();
         assertThat(patternListIterator.next(), is("[a-zA-Z]"));
     }
+
+    /**
+     * Checks invalid pattern sub-statement.
+     */
+    @Test(expected = ParserException.class)
+    public void processInvalidPatternSubStatements() throws IOException, ParserException {
+        YangNode node = manager.getDataModel("src/test/resources/InvalidPatternSubStatements.yang");
+    }
 }
diff --git a/src/test/resources/InvalidPatternSubStatements.yang b/src/test/resources/InvalidPatternSubStatements.yang
new file mode 100644
index 0000000..76ff75e
--- /dev/null
+++ b/src/test/resources/InvalidPatternSubStatements.yang
@@ -0,0 +1,13 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type string {
+            pattern "[a-zA-Z]\" {
+                description "pattern description";
+                reference "pattern reference";
+            }
+         }
+    }
+}