diff --git a/mmtk/src/julia_scanning.rs b/mmtk/src/julia_scanning.rs
index 39b1526..3fde85a 100644
--- a/mmtk/src/julia_scanning.rs
+++ b/mmtk/src/julia_scanning.rs
@@ -138,6 +138,11 @@ unsafe fn scan_julia_hidden_ptr_n<T>(
 // INFO: *_custom() functions are acessors to bitfields that do not use bindgen generated code.
 #[inline(always)]
 pub unsafe fn scan_julia_object<SV: SlotVisitor<JuliaVMSlot>>(obj: Address, closure: &mut SV) {
+    if crate::object_model::is_addr_in_immortalspace(obj) {
+        // immortal space objects do not need to be scanned
+        return;
+    }
+
     // get Julia object type
     let mut vtag = mmtk_jl_typetagof(obj);
     let mut vtag_usize = vtag.as_usize();
diff --git a/mmtk/src/object_model.rs b/mmtk/src/object_model.rs
index d1317fe..cb465fb 100644
--- a/mmtk/src/object_model.rs
+++ b/mmtk/src/object_model.rs
@@ -318,6 +318,11 @@ pub fn is_object_in_nonmoving(object: &ObjectReference) -> bool {
         && (*object).to_raw_address().as_usize() < 0xa00_0000_0000
 }
 
+#[inline(always)]
+pub fn is_addr_in_immortalspace(addr: Address) -> bool {
+    addr.as_usize() >= 0x400_0000_0000 && addr.as_usize() < 0x600_0000_0000
+}
+
 // If an object has its type tag bits set as 'smalltag', but those bits are not recognizable,
 // very possibly the object is corrupted. This function asserts this case.
 pub fn assert_generic_datatype(obj: Address) {