diff --git a/asm/src/main/java/dev/openrs2/asm/classpath/Library.java b/asm/src/main/java/dev/openrs2/asm/classpath/Library.java
index 2e1be257..de170881 100644
--- a/asm/src/main/java/dev/openrs2/asm/classpath/Library.java
+++ b/asm/src/main/java/dev/openrs2/asm/classpath/Library.java
@@ -161,7 +161,7 @@ public final class Library implements Iterable<ClassNode> {
 
 			try (
 				var in = new JarInputStream(Files.newInputStream(temp));
-				var out = new GZIPOutputStream(new SkipOutputStream(Files.newOutputStream(path), 2))
+				var out = new GZIPOutputStream(new SkipOutputStream(Files.newOutputStream(path), GZIP_HEADER.length))
 			) {
 				Pack200.newPacker().pack(in, out);
 			}