diff --git a/src/libcore/task.rs b/src/libcore/task.rs
index 4ab4a7ff7ea7d..b95bf7bf097d5 100644
--- a/src/libcore/task.rs
+++ b/src/libcore/task.rs
@@ -44,7 +44,6 @@ export add_wrapper;
 export run;
 
 export future_result;
-export unsupervise;
 export run_listener;
 export run_with;
 
diff --git a/src/rt/rust_builtin.cpp b/src/rt/rust_builtin.cpp
index 784df64d94488..34d3dd0728f65 100644
--- a/src/rt/rust_builtin.cpp
+++ b/src/rt/rust_builtin.cpp
@@ -127,11 +127,6 @@ rust_env_pairs() {
 }
 #endif
 
-extern "C" CDECL void
-unsupervise() {
-    // FIXME(#1789): bblum: remove this; requires a snapshot
-}
-
 extern "C" CDECL void
 vec_reserve_shared_actual(type_desc* ty, rust_vec_box** vp,
                           size_t n_elts) {
diff --git a/src/rt/rustrt.def.in b/src/rt/rustrt.def.in
index 62fb8482ad513..5d35b30086bfc 100644
--- a/src/rt/rustrt.def.in
+++ b/src/rt/rustrt.def.in
@@ -68,7 +68,6 @@ vec_from_buf_shared
 task_clear_event_reject
 task_wait_event
 task_signal_event
-unsupervise
 upcall_cmp_type
 upcall_fail
 upcall_trace