diff --git a/src/rt/rust.cpp b/src/rt/rust.cpp
index efb3d3eab374..0c7ec8d3abef 100644
--- a/src/rt/rust.cpp
+++ b/src/rt/rust.cpp
@@ -80,10 +80,7 @@ extern "C" CDECL int
 rust_start(uintptr_t main_fn, rust_crate const *crate, int argc,
            char **argv, void* crate_map) {
 
-    if (crate->abi_tag != ABI_X86_RUSTBOOT_CDECL)
-        update_log_settings(crate_map, getenv("RUST_LOG"));
-    else
-        update_log_settings(NULL, getenv("RUST_LOG"));
+    update_log_settings(crate_map, getenv("RUST_LOG"));
     rust_srv *srv = new rust_srv();
     rust_kernel *kernel = new rust_kernel(srv);
     kernel->start();
diff --git a/src/rt/rust_crate_cache.cpp b/src/rt/rust_crate_cache.cpp
index 3ab4a822e2ea..a4b7a79272bf 100644
--- a/src/rt/rust_crate_cache.cpp
+++ b/src/rt/rust_crate_cache.cpp
@@ -215,14 +215,6 @@ rust_crate_cache::get_type_desc(size_t size,
         // FIXME (issue #136):  Below is a miscalculation.
         td->is_stateful |= descs[i]->is_stateful;
     }
-    if (crate->abi_tag == ABI_X86_RUSTBOOT_CDECL) {
-        adjust_disp(td->copy_glue_off, descs[0], td);
-        adjust_disp(td->drop_glue_off, descs[0], td);
-        adjust_disp(td->free_glue_off, descs[0], td);
-        adjust_disp(td->mark_glue_off, descs[0], td);
-        adjust_disp(td->sever_glue_off, descs[0], td);
-        adjust_disp(td->obj_drop_glue_off, descs[0], td);
-    }
     HASH_ADD(hh, this->type_descs, descs, keysz, td);
     return td;
 }
diff --git a/src/rt/rust_internal.h b/src/rt/rust_internal.h
index 29e36fcd72dc..a1b9be9bf6f8 100644
--- a/src/rt/rust_internal.h
+++ b/src/rt/rust_internal.h
@@ -90,10 +90,6 @@ static size_t const TIME_SLICE_IN_MS = 10;
 
 static intptr_t const CONST_REFCOUNT = 0x7badface;
 
-// ABI tags for rust_start, rust_task::start and friends.
-static uintptr_t const ABI_X86_RUSTBOOT_CDECL = 1;
-static uintptr_t const ABI_X86_RUSTC_FASTCALL = 2;
-
 // This accounts for logging buffers.
 
 static size_t const BUF_BYTES = 2048;
diff --git a/src/rt/rust_upcall.cpp b/src/rt/rust_upcall.cpp
index a1569f07e450..084b025d7016 100644
--- a/src/rt/rust_upcall.cpp
+++ b/src/rt/rust_upcall.cpp
@@ -566,7 +566,6 @@ extern "C" CDECL rust_task *
 upcall_start_task(rust_task *spawner,
                   rust_task *task,
                   uintptr_t exit_task_glue,
-                  uintptr_t spawnee_abi,
                   uintptr_t spawnee_fn,
                   size_t callsz) {
     LOG_UPCALL_ENTRY(spawner);
@@ -631,7 +630,6 @@ extern "C" CDECL maybe_proxy<rust_task> *
 upcall_start_thread(rust_task *task,
                     rust_proxy<rust_task> *child_task_proxy,
                     uintptr_t exit_task_glue,
-                    uintptr_t spawnee_abi,
                     uintptr_t spawnee_fn,
                     size_t callsz) {
     LOG_UPCALL_ENTRY(task);