diff --git a/core/src/entry_point/start_item_arm.rs b/core/src/entry_point/start_item_arm.rs
index 5d88d6b..4cdaef9 100644
--- a/core/src/entry_point/start_item_arm.rs
+++ b/core/src/entry_point/start_item_arm.rs
@@ -20,16 +20,16 @@ pub unsafe extern "C" fn _start() -> ! {
         subw r4, pc, #4    // r4 = pc
         ldr r5, =.start   // r5 = address of .start
         cmp r4, r5
-        beq .Lstack_init  // Jump to stack initialization if pc was correct
+        beq 2f  // Jump to stack initialization if pc was correct
         movw r0, #8       // LowLevelDebug driver number
         movw r1, #1       // LowLevelDebug 'print status code' command
         movw r2, #2       // LowLevelDebug relocation failed status code
         svc 2             // command() syscall
-        .Lyield_loop:
+        1:
         svc 0             // yield() syscall (in infinite loop)
-        b .Lyield_loop
+        b 1b
 
-        .Lstack_init:
+        2:
         // Compute the stacktop (stack_start). The stacktop is computed as
         // stack_size + mem_start plus padding to align the stack to a multiple
         // of 8 bytes. The 8 byte alignment is to follow ARM AAPCS:
diff --git a/rust-toolchain b/rust-toolchain
index 1674405..64ed934 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1,7 +1,7 @@
 [toolchain]
 # See https://rust-lang.github.io/rustup-components-history/ for a list of
 # recently nightlies and what components are available for them.
-channel = "nightly-2021-03-25"
+channel = "nightly-2021-10-21"
 components = ["clippy", "miri", "rustfmt"]
 targets = ["thumbv7em-none-eabi",
            "riscv32imac-unknown-none-elf",