diff --git a/tests/tests/derive.rs b/tests/tests/derive.rs
index 91224e0..df46084 100644
--- a/tests/tests/derive.rs
+++ b/tests/tests/derive.rs
@@ -1,4 +1,5 @@
 #![cfg(feature = "derive")]
+#![allow(dead_code)]
 
 use valuable::Valuable;
 
diff --git a/tests/tests/ui/not_valuable.stderr b/tests/tests/ui/not_valuable.stderr
index 9992dfb..60af2c0 100644
--- a/tests/tests/ui/not_valuable.stderr
+++ b/tests/tests/ui/not_valuable.stderr
@@ -5,17 +5,17 @@ error[E0277]: the trait bound `S: Valuable` is not satisfied
   |          -------- required by a bound introduced by this call
 6 | struct Struct {
 7 |     f: Option<S>,
-  |        ^^^^^^^^^ the trait `Valuable` is not implemented for `S`
+  |        ^^^^^^^^^ the trait `Valuable` is not implemented for `S`, which is required by `Option<S>: Valuable`
   |
   = help: the following other types implement trait `Valuable`:
-            bool
-            char
-            isize
-            i8
-            i16
-            i32
-            i64
-            i128
+            &T
+            &[T]
+            &mut T
+            &std::path::Path
+            &str
+            ()
+            (T0, T1)
+            (T0, T1, T2)
           and $N others
   = note: required for `Option<S>` to implement `Valuable`
 
@@ -25,17 +25,17 @@ error[E0277]: the trait bound `S: Valuable` is not satisfied
 10 | #[derive(Valuable)]
    |          -------- required by a bound introduced by this call
 11 | struct Tuple(Option<S>);
-   |              ^^^^^^^^^ the trait `Valuable` is not implemented for `S`
+   |              ^^^^^^^^^ the trait `Valuable` is not implemented for `S`, which is required by `Option<S>: Valuable`
    |
    = help: the following other types implement trait `Valuable`:
-             bool
-             char
-             isize
-             i8
-             i16
-             i32
-             i64
-             i128
+             &T
+             &[T]
+             &mut T
+             &std::path::Path
+             &str
+             ()
+             (T0, T1)
+             (T0, T1, T2)
            and $N others
    = note: required for `Option<S>` to implement `Valuable`
 
@@ -46,17 +46,17 @@ error[E0277]: the trait bound `S: Valuable` is not satisfied
    |          -------- required by a bound introduced by this call
 14 | enum Enum {
 15 |     Struct { f: Option<S> },
-   |                 ^^^^^^^^^ the trait `Valuable` is not implemented for `S`
+   |                 ^^^^^^^^^ the trait `Valuable` is not implemented for `S`, which is required by `&Option<S>: Valuable`
    |
    = help: the following other types implement trait `Valuable`:
-             bool
-             char
-             isize
-             i8
-             i16
-             i32
-             i64
-             i128
+             &T
+             &[T]
+             &mut T
+             &std::path::Path
+             &str
+             ()
+             (T0, T1)
+             (T0, T1, T2)
            and $N others
    = note: required for `Option<S>` to implement `Valuable`
    = note: 1 redundant requirement hidden
@@ -69,17 +69,17 @@ error[E0277]: the trait bound `S: Valuable` is not satisfied
    |          -------- required by a bound introduced by this call
 ...
 16 |     Tuple(Option<S>),
-   |           ^^^^^^^^^ the trait `Valuable` is not implemented for `S`
+   |           ^^^^^^^^^ the trait `Valuable` is not implemented for `S`, which is required by `&Option<S>: Valuable`
    |
    = help: the following other types implement trait `Valuable`:
-             bool
-             char
-             isize
-             i8
-             i16
-             i32
-             i64
-             i128
+             &T
+             &[T]
+             &mut T
+             &std::path::Path
+             &str
+             ()
+             (T0, T1)
+             (T0, T1, T2)
            and $N others
    = note: required for `Option<S>` to implement `Valuable`
    = note: 1 redundant requirement hidden
diff --git a/valuable/build.rs b/valuable/build.rs
index ad0dd06..77a8645 100644
--- a/valuable/build.rs
+++ b/valuable/build.rs
@@ -8,6 +8,9 @@ include!("no_atomic.rs");
 // opening a GitHub issue if your build environment requires some way to enable
 // these cfgs other than by executing our build script.
 fn main() {
+    println!("cargo:rerun-if-changed=no_atomic.rs");
+    println!("cargo:rustc-check-cfg=cfg(valuable_no_atomic_cas,valuable_no_atomic,valuable_no_atomic_64)");
+
     let target = match env::var("TARGET") {
         Ok(target) => target,
         Err(e) => {
@@ -34,6 +37,4 @@ fn main() {
     } else {
         // Otherwise, assuming `"max-atomic-width" == 64`.
     }
-
-    println!("cargo:rerun-if-changed=no_atomic.rs");
 }
diff --git a/valuable/no_atomic.rs b/valuable/no_atomic.rs
index 1df2439..d679dfe 100644
--- a/valuable/no_atomic.rs
+++ b/valuable/no_atomic.rs
@@ -28,6 +28,7 @@ const NO_ATOMIC_64: &[&str] = &[
     "csky-unknown-linux-gnuabiv2",
     "csky-unknown-linux-gnuabiv2hf",
     "hexagon-unknown-linux-musl",
+    "hexagon-unknown-none-elf",
     "m68k-unknown-linux-gnu",
     "mips-unknown-linux-gnu",
     "mips-unknown-linux-musl",
@@ -52,9 +53,11 @@ const NO_ATOMIC_64: &[&str] = &[
     "riscv32gc-unknown-linux-musl",
     "riscv32i-unknown-none-elf",
     "riscv32im-unknown-none-elf",
+    "riscv32ima-unknown-none-elf",
     "riscv32imac-esp-espidf",
     "riscv32imac-unknown-none-elf",
     "riscv32imac-unknown-xous-elf",
+    "riscv32imafc-esp-espidf",
     "riscv32imafc-unknown-none-elf",
     "riscv32imc-esp-espidf",
     "riscv32imc-unknown-none-elf",