diff --git a/src/main/java/net/fabricmc/loader/impl/launch/knot/KnotClassDelegate.java b/src/main/java/net/fabricmc/loader/impl/launch/knot/KnotClassDelegate.java
index b6dc2ac23..2446ae622 100644
--- a/src/main/java/net/fabricmc/loader/impl/launch/knot/KnotClassDelegate.java
+++ b/src/main/java/net/fabricmc/loader/impl/launch/knot/KnotClassDelegate.java
@@ -499,7 +499,7 @@ private byte[] getRawClassByteArray(String name, boolean allowFromParent) throws
 			url = parentClassLoader.getResource(name);
 
 			if (!isValidParentUrl(url, name)) {
-				if (LOG_CLASS_LOAD) Log.info(LogCategory.KNOT, "refusing to load class %s at %s from parent class loader", name, getCodeSource(url, name));
+				if (LOG_CLASS_LOAD) Log.info(LogCategory.KNOT, "refusing to load class %s at %s from parent class loader", name, url != null ? getCodeSource(url, name) : "null");
 
 				return null;
 			}