diff --git a/pom.xml b/pom.xml
index f8a3083..83ea0e4 100644
--- a/pom.xml
+++ b/pom.xml
@@ -22,7 +22,7 @@
         <dependency>
             <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-install-plugin</artifactId>
-            <version>2.4</version>
+            <version>3.1.1</version>
             <type>maven-plugin</type>
         </dependency>
 
diff --git a/src/main/java/interpreter/grammar/Main.java b/src/main/java/interpreter/grammar/Main.java
index 4d1abb7..0d02779 100644
--- a/src/main/java/interpreter/grammar/Main.java
+++ b/src/main/java/interpreter/grammar/Main.java
@@ -27,7 +27,7 @@ public class Main {
             }
         }
 
-        ANTLRInputStream input = null;
+        ANTLRInputStream input;
         try {
             input = new ANTLRFileStream(args[0]);
         } catch (IOException e) {