diff --git a/audiotags-dev-macro/src/lib.rs b/audiotags-dev-macro/src/lib.rs
index 15646ff..c8e6ed9 100644
--- a/audiotags-dev-macro/src/lib.rs
+++ b/audiotags-dev-macro/src/lib.rs
@@ -70,8 +70,8 @@ macro_rules! impl_tag {
         }
 
         // From dyn AudioTag to wrapper (any type)
-        impl From<Box<dyn AudioTag>> for $tag {
-            fn from(inp: Box<dyn AudioTag>) -> Self {
+        impl From<Box<dyn AudioTag + Send + Sync>> for $tag {
+            fn from(inp: Box<dyn AudioTag + Send + Sync>) -> Self {
                 let mut inp = inp;
                 if let Some(t_refmut) = inp.to_any_mut().downcast_mut::<$tag>() {
                     let t = std::mem::replace(t_refmut, $tag::new()); // TODO: can we avoid creating the dummy tag?
@@ -85,8 +85,8 @@ macro_rules! impl_tag {
             }
         }
         // From dyn AudioTag to inner (any type)
-        impl std::convert::From<Box<dyn AudioTag>> for $inner {
-            fn from(inp: Box<dyn AudioTag>) -> Self {
+        impl std::convert::From<Box<dyn AudioTag + Send + Sync>> for $inner {
+            fn from(inp: Box<dyn AudioTag + Send + Sync>) -> Self {
                 let t: $tag = inp.into();
                 t.into()
             }
diff --git a/src/lib.rs b/src/lib.rs
index ba8af21..0109f52 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -136,7 +136,7 @@ impl Tag {
             config,
         }
     }
-    pub fn read_from_path(&self, path: impl AsRef<Path>) -> crate::Result<Box<dyn AudioTag>> {
+    pub fn read_from_path(&self, path: impl AsRef<Path>) -> crate::Result<Box<dyn AudioTag + Send + Sync>> {
         match self.tag_type.unwrap_or(TagType::try_from_ext(
             path.as_ref()
                 .extension()