diff --git a/src/main/java/fr/packageviewer/distribution/ArchDistribution.java b/src/main/java/fr/packageviewer/distribution/ArchDistribution.java
index 492f535..56a8eaf 100644
--- a/src/main/java/fr/packageviewer/distribution/ArchDistribution.java
+++ b/src/main/java/fr/packageviewer/distribution/ArchDistribution.java
@@ -132,11 +132,15 @@ public class ArchDistribution implements Distribution {
                 futureDeps.add(getPackageTree(depPackageName, depth - 1));
             }
             for(CompletableFuture<Package> future : futureDeps){
+                Package dep;
                 try {
-                    deps.add(future.get());
+                    dep = future.get();
                 } catch (InterruptedException | ExecutionException e) {
                     throw new RuntimeException(e);
                 }
+                if(dep!=null){
+                    deps.add(dep);
+                }
             }
 
             // TODO this doesn't seem clean