diff --git a/artiq/firmware/ksupport/eh.rs b/artiq/firmware/ksupport/eh.rs
index 6138969a4..5cd220bbc 100644
--- a/artiq/firmware/ksupport/eh.rs
+++ b/artiq/firmware/ksupport/eh.rs
@@ -398,7 +398,7 @@ static mut INFLIGHT: ExceptionInfo = ExceptionInfo {
 };
 
 #[export_name="__artiq_raise"]
-#[unwind]
+#[unwind(allowed)]
 pub unsafe extern fn raise(exception: *const Exception) -> ! {
     // Zing! The Exception<'a> to Exception<'static> transmute is not really sound in case
     // the exception is ever captured. Fortunately, they currently aren't, and we save
@@ -416,7 +416,7 @@ pub unsafe extern fn raise(exception: *const Exception) -> ! {
 }
 
 #[export_name="__artiq_reraise"]
-#[unwind]
+#[unwind(allowed)]
 pub unsafe extern fn reraise() -> ! {
     if INFLIGHT.handled {
         raise(&INFLIGHT.exception.unwrap())
diff --git a/artiq/firmware/runtime/profiler.rs b/artiq/firmware/runtime/profiler.rs
index 0e4380f96..e3c47e1a0 100644
--- a/artiq/firmware/runtime/profiler.rs
+++ b/artiq/firmware/runtime/profiler.rs
@@ -2,16 +2,16 @@
 
 use core::mem;
 use core::fmt;
-use core::nonzero::NonZero;
+use core::num::NonZeroUsize;
 use alloc::Vec;
 use managed::ManagedMap;
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
-pub struct Address(NonZero<usize>);
+pub struct Address(NonZeroUsize);
 
 impl Address {
     pub fn new(raw: usize) -> Option<Address> {
-        NonZero::new(raw).map(Address)
+        NonZeroUsize::new(raw).map(Address)
     }
 
     pub fn as_raw(&self) -> usize {
diff --git a/conda/artiq-dev/meta.yaml b/conda/artiq-dev/meta.yaml
index 62d283af0..62629e2a2 100644
--- a/conda/artiq-dev/meta.yaml
+++ b/conda/artiq-dev/meta.yaml
@@ -21,7 +21,7 @@ requirements:
     - binutils-or1k-linux >=2.27
     - llvm-or1k 6.0.0
     - llvmlite-artiq 0.23.0.dev py35_4
-    - rust-core-or1k 1.25.0 20
+    - rust-core-or1k 1.26.0 21
     - openocd 0.10.0 6
     - lit
     - outputcheck