diff --git a/core/src/main/java/io/micronaut/core/io/IOUtils.java b/core/src/main/java/io/micronaut/core/io/IOUtils.java
index 32e2d443512..48fd337a835 100644
--- a/core/src/main/java/io/micronaut/core/io/IOUtils.java
+++ b/core/src/main/java/io/micronaut/core/io/IOUtils.java
@@ -90,9 +90,9 @@ public static void eachFile(@NonNull URI uri, String path, @NonNull Consumer<Pat
                     // Basically ignores anything after the !/ if it exists, and uses the part
                     // before as the jar path to extract.
                     String jarUri = uri.getSchemeSpecificPart();
-                    int sep = jarUri.lastIndexOf("!/");
+                    int sep = jarUri.toLowerCase().lastIndexOf(".jar!/");
                     if (sep != -1) {
-                        jarUri = jarUri.substring(0, sep);
+                        jarUri = jarUri.substring(0, sep+4);
                     }
                     // now, add the !/ at the end again so that loadNestedJarUri can handle it:
                     jarUri += "!/";