diff --git a/resource/src/lib.rs b/resource/src/lib.rs
index 508961d5..3aff4c93 100644
--- a/resource/src/lib.rs
+++ b/resource/src/lib.rs
@@ -72,7 +72,7 @@ mod test {
     pub const F5_LEN: usize = 20;
 
     pub type MyGraph = Vec<[SimpleTerm<'static>; 3]>;
-    pub type TestResult = Result<(), Box<dyn std::error::Error>>;
+    pub type TestResult = Result<(), Box<dyn std::error::Error + Send + Sync + 'static>>;
 
     pub fn make_loader() -> LocalLoader {
         let ns = NS.map_unchecked(MownStr::from);
diff --git a/resource/src/loader/_error.rs b/resource/src/loader/_error.rs
index 7368f477..f33febd0 100644
--- a/resource/src/loader/_error.rs
+++ b/resource/src/loader/_error.rs
@@ -20,7 +20,7 @@ pub enum LoaderError {
     CantGuessSyntax(IriBuf),
     /// An error was encountered while parsing the data into an RDF graph
     #[error("Can not parse {0:?}: {1}")]
-    ParseError(IriBuf, Box<dyn std::error::Error>),
+    ParseError(IriBuf, Box<dyn std::error::Error + Send + Sync + 'static>),
 }
 
 impl LoaderError {
diff --git a/resource/src/resource/_error.rs b/resource/src/resource/_error.rs
index 13b6628f..125786d5 100644
--- a/resource/src/resource/_error.rs
+++ b/resource/src/resource/_error.rs
@@ -70,7 +70,10 @@ pub enum ResourceError<E: Error + Send + Sync + 'static> {
     },
 }
 
-impl<E: Error + Send + Sync + 'static> ResourceError<E> {
+impl<E: Error + Send + Sync + 'static> ResourceError<E>
+where
+    Self: Send + Sync + 'static,
+{
     /// The identifier of the resource raising the error.
     ///
     /// NB: for errors raised during creation ([`ResourceError::IriNotAbsolute`], [`ResourceError::LoaderError`]),
@@ -103,7 +106,7 @@ impl<E: Error + Send + Sync + 'static> From<crate::loader::LoaderError> for Reso
     }
 }
 
-impl<E: Error + Send + Sync + 'static> Error for ResourceError<E> {}
+impl<E: Error + Send + Sync + 'static> Error for ResourceError<E> where Self: Send + Sync + 'static {}
 
 /// A result whose error is a [`ResourceError`]
 pub type ResourceResult<T, G> = Result<T, ResourceError<<G as Graph>::Error>>;
diff --git a/resource/src/resource/_struct.rs b/resource/src/resource/_struct.rs
index 5860800f..fd2062ca 100644
--- a/resource/src/resource/_struct.rs
+++ b/resource/src/resource/_struct.rs
@@ -22,6 +22,7 @@ pub struct Resource<G, L> {
 impl<G, L> Resource<G, L>
 where
     G: Graph + 'static,
+    G::Error: Send + Sync + 'static,
     L: Loader,
 {
     /// Constructor
diff --git a/resource/src/resource/test.rs b/resource/src/resource/test.rs
index 56948db5..467744ad 100644
--- a/resource/src/resource/test.rs
+++ b/resource/src/resource/test.rs
@@ -597,6 +597,8 @@ fn no_reload() -> TestResult {
     Ok(())
 }
 
-fn make_rsc(iri: Iri<&str>) -> Result<Resource<MyGraph, LocalLoader>, Box<dyn std::error::Error>> {
+fn make_rsc(
+    iri: Iri<&str>,
+) -> Result<Resource<MyGraph, LocalLoader>, Box<dyn std::error::Error + Send + Sync + 'static>> {
     Ok(make_loader().arced().get_resource(iri)?)
 }