diff --git a/src/main/java/GTNHNightlyUpdater/Updater.java b/src/main/java/GTNHNightlyUpdater/Updater.java
index 7bc8ad1..d40174b 100644
--- a/src/main/java/GTNHNightlyUpdater/Updater.java
+++ b/src/main/java/GTNHNightlyUpdater/Updater.java
@@ -99,7 +99,7 @@ void updateModpackMods(Assets.Asset assets, Path modCacheDir, Set<String> modExc
             if (packMods.containsKey(modVersionToUse.filename().toLowerCase())) {
                 continue;
             }
-            if (packMods.containsKey(modVersionToUse.mavenFilename().toLowerCase())) {
+            if (modVersionToUse.mavenFilename() != null && packMods.containsKey(modVersionToUse.mavenFilename().toLowerCase())) {
                 continue;
             }
 
@@ -249,7 +249,7 @@ void cacheMods(Assets.Asset asset, Path modCacheDir) throws IOException, Interru
                 }
             }
 
-            if (Files.exists(modCacheDir.resolve(modVersionToUse.filename())) || Files.exists(modCacheDir.resolve(modVersionToUse.mavenFilename()))) {
+            if (Files.exists(modCacheDir.resolve(modVersionToUse.filename())) || (modVersionToUse.mavenFilename() != null && Files.exists(modCacheDir.resolve(modVersionToUse.mavenFilename())))) {
                 continue;
             }