diff --git a/src/rt/rust_task.cpp b/src/rt/rust_task.cpp
index 7ef3975fd51c..ca85411e9d5e 100644
--- a/src/rt/rust_task.cpp
+++ b/src/rt/rust_task.cpp
@@ -57,7 +57,6 @@ rust_task::rust_task(rust_scheduler *sched, rust_task_list *state,
     ref_count(1),
     stk(NULL),
     runtime_sp(0),
-    gc_alloc_chain(0),
     sched(sched),
     cache(NULL),
     kernel(sched->kernel),
diff --git a/src/rt/rust_task.h b/src/rt/rust_task.h
index afc6f682ceb0..5513cd9e2828 100644
--- a/src/rt/rust_task.h
+++ b/src/rt/rust_task.h
@@ -59,7 +59,6 @@ rust_task : public kernel_owned<rust_task>, rust_cond
     context ctx;
     stk_seg *stk;
     uintptr_t runtime_sp;      // Runtime sp while task running.
-    rust_box *gc_alloc_chain;      // Linked list of GC allocations.
     rust_scheduler *sched;
     rust_crate_cache *cache;
 
diff --git a/src/rt/rust_upcall.cpp b/src/rt/rust_upcall.cpp
index 778e90df162c..79291bdd3a3b 100644
--- a/src/rt/rust_upcall.cpp
+++ b/src/rt/rust_upcall.cpp
@@ -57,9 +57,8 @@ upcall_malloc(rust_task *task, size_t nbytes, type_desc *td) {
     LOG_UPCALL_ENTRY(task);
 
     LOG(task, mem,
-        "upcall malloc(%" PRIdPTR ", 0x%" PRIxPTR ")"
-        " with gc-chain head = 0x%" PRIxPTR,
-        nbytes, td, task->gc_alloc_chain);
+        "upcall malloc(%" PRIdPTR ", 0x%" PRIxPTR ")",
+        nbytes, td);
 
     gc::maybe_gc(task);
 
@@ -69,10 +68,8 @@ upcall_malloc(rust_task *task, size_t nbytes, type_desc *td) {
     void *p = task->malloc(nbytes, "tdesc", td);
 
     LOG(task, mem,
-        "upcall malloc(%" PRIdPTR ", 0x%" PRIxPTR
-        ") = 0x%" PRIxPTR
-        " with gc-chain head = 0x%" PRIxPTR,
-        nbytes, td, (uintptr_t)p, task->gc_alloc_chain);
+        "upcall malloc(%" PRIdPTR ", 0x%" PRIxPTR ") = 0x%" PRIxPTR,
+        nbytes, td, (uintptr_t)p);
     return (uintptr_t) p;
 }