diff --git a/launcher-builder/src/main/java/com/skcraft/launcher/builder/loaders/ModernForgeLoaderProcessor.java b/launcher-builder/src/main/java/com/skcraft/launcher/builder/loaders/ModernForgeLoaderProcessor.java
index b21b63f..b59201b 100644
--- a/launcher-builder/src/main/java/com/skcraft/launcher/builder/loaders/ModernForgeLoaderProcessor.java
+++ b/launcher-builder/src/main/java/com/skcraft/launcher/builder/loaders/ModernForgeLoaderProcessor.java
@@ -150,6 +150,22 @@
 				// Add loader manifest to the map
 				manifest.getLoaders().put(loaderName, new LoaderManifest(profile.getLibraries(), profile.getData(), extraFiles));
 
+				// Find name of final patched library and mark it as excluded from download
+				// TODO: we should generalize this to all process outputs, really
+				SidedData<String> finalJars = profile.getData().get("PATCHED");
+				if (finalJars != null) {
+					String libraryName = finalJars.getClient();
+					libraryName = libraryName.substring(1, libraryName.length() - 1);
+
+					for (Library lib : result.getLoaderLibraries()) {
+						if (lib.getName().equals(libraryName)) {
+							lib.setGenerated(true);
+							log.info(String.format("Setting generated flag on library '%s'", lib.getName()));
+							break;
+						}
+					}
+				}
+
 				// Add processors
 				manifest.getTasks().addAll(profile.toProcessorEntries(loaderName));
 			}
diff --git a/launcher/src/main/java/com/skcraft/launcher/model/minecraft/Library.java b/launcher/src/main/java/com/skcraft/launcher/model/minecraft/Library.java
index f6cd2d8..2fa1c35 100644
--- a/launcher/src/main/java/com/skcraft/launcher/model/minecraft/Library.java
+++ b/launcher/src/main/java/com/skcraft/launcher/model/minecraft/Library.java
@@ -8,6 +8,7 @@
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.google.common.base.Joiner;
 import com.google.common.base.Splitter;
 import com.google.common.collect.Lists;
@@ -33,7 +34,8 @@
     private String comment;
 
     // Custom
-    private boolean locallyAvailable;
+    @JsonInclude(value = JsonInclude.Include.NON_DEFAULT)
+    private boolean generated;
 
     public boolean matches(Environment environment) {
         boolean allow = false;
diff --git a/launcher/src/main/java/com/skcraft/launcher/update/BaseUpdater.java b/launcher/src/main/java/com/skcraft/launcher/update/BaseUpdater.java
index e447ef0..ea6dff0 100644
--- a/launcher/src/main/java/com/skcraft/launcher/update/BaseUpdater.java
+++ b/launcher/src/main/java/com/skcraft/launcher/update/BaseUpdater.java
@@ -249,6 +249,8 @@
         }
 
         for (Library library : allLibraries) {
+            if (library.isGenerated()) continue; // Skip generated libraries.
+
             if (library.matches(environment)) {
                 checkInterrupted();