diff --git a/src/main/java/diff/rednaga/AXMLPrinter.java b/src/main/java/diff/rednaga/AXMLPrinter.java
index eeb020d..156deb4 100644
--- a/src/main/java/diff/rednaga/AXMLPrinter.java
+++ b/src/main/java/diff/rednaga/AXMLPrinter.java
@@ -78,8 +78,13 @@ public static void main(String[] arguments) throws IOException {
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
-            fileInputStream.close();
-            fileOutputStream.close();
+            if (fileInputStream != null) {
+                fileInputStream.close();
+            }
+
+            if (fileOutputStream != null) {
+                fileOutputStream.close();
+            }
         }
     }