diff --git a/src/lib.rs b/src/lib.rs
index e20c23c..08a9c78 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1558,12 +1558,12 @@ macro_rules! location {
 #[snafu(crate_root(crate))]
 #[snafu(whatever)]
 #[snafu(display("{message}"))]
-#[snafu(provide(opt, ref, chain, dyn std::error::Error => source.as_deref()))]
+#[snafu(provide(opt, ref, chain, dyn std::error::Error + Send + Sync => source.as_deref()))]
 #[cfg(any(feature = "std", test))]
 pub struct Whatever {
-    #[snafu(source(from(Box<dyn std::error::Error>, Some)))]
+    #[snafu(source(from(Box<dyn std::error::Error + Send + Sync>, Some)))]
     #[snafu(provide(false))]
-    source: Option<Box<dyn std::error::Error>>,
+    source: Option<Box<dyn std::error::Error + Send + Sync>>,
     message: String,
     backtrace: Backtrace,
 }
diff --git a/tests/backtrace.rs b/tests/backtrace.rs
index b0fa7fe..3f85718 100644
--- a/tests/backtrace.rs
+++ b/tests/backtrace.rs
@@ -130,7 +130,7 @@ mod whatever_nested {
         not_a_whatever().with_whatever_context(|_| format!("Outer failure"))
     }
 
-    fn not_a_whatever() -> Result<(), Box<dyn std::error::Error>> {
+    fn not_a_whatever() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
         inner_whatever().map_err(Into::into)
     }