diff --git a/.gitignore b/.gitignore
index 6dfcc3af..08410ef4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,4 +12,4 @@ WORKSPACE.bazel
 bazel-*
 
 # Emacs backups
-*~
\ No newline at end of file
+*~
diff --git a/insta/src/redaction.rs b/insta/src/redaction.rs
index 61c7f67b..6f017aaa 100644
--- a/insta/src/redaction.rs
+++ b/insta/src/redaction.rs
@@ -54,7 +54,7 @@ pub enum Redaction {
     /// Static redaction with new content.
     Static(Content),
     /// Redaction with new content.
-    Dynamic(Box<dyn Fn(Content, ContentPath<'_>) -> Content + Sync + Send>),
+    Dynamic(Box<dyn Fn(Content, ContentPath<'_>) -> Content>),
 }
 
 macro_rules! impl_from {
@@ -127,7 +127,7 @@ impl<'a> From<&'a [u8]> for Redaction {
 pub fn dynamic_redaction<I, F>(func: F) -> Redaction
 where
     I: Into<Content>,
-    F: Fn(Content, ContentPath<'_>) -> I + Send + Sync + 'static,
+    F: Fn(Content, ContentPath<'_>) -> I + 'static,
 {
     Redaction::Dynamic(Box::new(move |c, p| func(c, p).into()))
 }
diff --git a/insta/src/settings.rs b/insta/src/settings.rs
index eb617c9b..ac82b207 100644
--- a/insta/src/settings.rs
+++ b/insta/src/settings.rs
@@ -413,7 +413,7 @@ impl Settings {
     pub fn add_dynamic_redaction<I, F>(&mut self, selector: &str, func: F)
     where
         I: Into<Content>,
-        F: Fn(Content, ContentPath<'_>) -> I + Send + Sync + 'static,
+        F: Fn(Content, ContentPath<'_>) -> I + 'static,
     {
         self.add_redaction(selector, dynamic_redaction(func));
     }