diff --git a/assets/prelude.ld b/assets/prelude.ld
index ee98016..3a2e60d 100644
--- a/assets/prelude.ld
+++ b/assets/prelude.ld
@@ -1137,7 +1137,7 @@ fn heed {
 fn send_sync {
 	"Sends the message to the specified process, and waits for a response in the form of a `(:reply, response)` tuple."
 	(pid, msg) -> {
-		send (pid, msg)
+		send! (pid, msg)
 		receive {
 			(:reply, res) -> res
 		}
@@ -1157,7 +1157,7 @@ fn request_fetch! {
 				request_fetch! (pid)
 			}
 			else {
-				send (pid, (:reply, unbox (fetch_inbox)))
+				send! (pid, (:reply, unbox (fetch_inbox)))
 				store! (fetch_inbox, ())
 			}
 	}
@@ -1167,7 +1167,7 @@ fn fetch {
 	"Requests the contents of the URL passed in. Returns a result tuple of (:ok, <contents>) or (:err, <status code>)."
 	(url) -> {
 		let pid = self ()
-		spawn! (fn () -> request_fetch! (pid, url))
+		spawn (fn () -> request_fetch! (pid, url))
 		receive {
 			(:reply, (_, response)) -> response
 		}
@@ -1182,7 +1182,7 @@ fn input_reader! {
 				input_reader! (pid)
 			}
 			else {
-				send (pid, (:reply, unbox (input)))
+				send! (pid, (:reply, unbox (input)))
 				store! (input, nil)
 			}
 	}
@@ -1192,7 +1192,7 @@ fn read_input {
 	"Waits until there is input in the input buffer, and returns it once there is."
 	() -> {
 		let pid = self ()
-		spawn! (fn () -> input_reader! (pid))
+		spawn (fn () -> input_reader! (pid))
 		receive {
 			(:reply, response) -> response
 		}
@@ -1390,10 +1390,10 @@ fn turtle_listener () -> {
 			add_command! (self (), (:loadstate, position, heading, visible?, pendown?, penwidth, pencolor))
 
 		}
-		(:pencolor, pid) -> send (pid, (:reply, do turtle_states > unbox > self () > :pencolor))
-		(:position, pid) -> send (pid, (:reply, do turtle_states > unbox > self () > :position))
-		(:penwidth, pid) -> send (pid, (:reply, do turtle_states > unbox > self () > :penwidth))
-		(:heading, pid) -> send (pid, (:reply, do turtle_states > unbox > self () > :heading))
+		(:pencolor, pid) -> send! (pid, (:reply, do turtle_states > unbox > self () > :pencolor))
+		(:position, pid) -> send! (pid, (:reply, do turtle_states > unbox > self () > :position))
+		(:penwidth, pid) -> send! (pid, (:reply, do turtle_states > unbox > self () > :penwidth))
+		(:heading, pid) -> send! (pid, (:reply, do turtle_states > unbox > self () > :heading))
 		does_not_understand -> {
 			let pid = self ()
 			panic! "{pid} does not understand message: {does_not_understand}"
@@ -1405,7 +1405,7 @@ fn turtle_listener () -> {
 fn spawn_turtle {
 	"Spawns a new turtle in a new process. Methods on the turtle process mirror those of turtle graphics functions in prelude. Returns the pid of the new turtle."
 	() -> {
-		let pid = spawn! (fn () -> turtle_listener ())
+		let pid = spawn (fn () -> turtle_listener ())
 		update! (turtle_states, assoc (_, pid, turtle_init))
 		pid
 	}
diff --git a/pkg/rudus_bg.wasm b/pkg/rudus_bg.wasm
index 96ba329..b9c00fc 100644
Binary files a/pkg/rudus_bg.wasm and b/pkg/rudus_bg.wasm differ