diff --git a/actix-cors/CHANGES.md b/actix-cors/CHANGES.md
index 02a95458e..277e24331 100644
--- a/actix-cors/CHANGES.md
+++ b/actix-cors/CHANGES.md
@@ -1,6 +1,7 @@
 # Changes
 
 ## Unreleased - 2020-xx-xx
+* Improve `allowed_origin_fn` to allow using of closures. [#110]
 
 
 ## 0.4.0 - 2020-09-27
@@ -9,7 +10,7 @@
 
 [#93]: https://github.com/actix/actix-extras/pull/93
 [#106]: https://github.com/actix/actix-extras/pull/106
-
+[#110]: https://github.com/actix/actix-extras/pull/110
 
 ## 0.3.0 - 2020-09-11
 * Update `actix-web` dependency to 3.0.0.
diff --git a/actix-cors/Cargo.toml b/actix-cors/Cargo.toml
index 99b41865e..d78eeec1e 100644
--- a/actix-cors/Cargo.toml
+++ b/actix-cors/Cargo.toml
@@ -23,3 +23,4 @@ futures-util = { version = "0.3.4", default-features = false }
 
 [dev-dependencies]
 actix-rt = "1.1.1"
+regex = "1.3.9"
diff --git a/actix-cors/src/lib.rs b/actix-cors/src/lib.rs
index d09657cda..726fba607 100644
--- a/actix-cors/src/lib.rs
+++ b/actix-cors/src/lib.rs
@@ -290,9 +290,14 @@ impl Cors {
     ///
     /// If the function returns `true`, the client's `Origin` request header will be echoed
     /// back into the `Access-Control-Allow-Origin` response header.
-    pub fn allowed_origin_fn(mut self, f: fn(req: &RequestHead) -> bool) -> Cors {
+    pub fn allowed_origin_fn<F>(mut self, f: F) -> Cors
+    where
+        F: (Fn(&RequestHead) -> bool) + 'static,
+    {
         if let Some(cors) = cors(&mut self.cors, &self.error) {
-            cors.origins_fns.push(OriginFn { f });
+            cors.origins_fns.push(OriginFn {
+                boxed_fn: Box::new(f),
+            });
         }
         self
     }
@@ -597,7 +602,7 @@ pub struct CorsMiddleware<S> {
 }
 
 struct OriginFn {
-    f: fn(req: &RequestHead) -> bool,
+    boxed_fn: Box<dyn Fn(&RequestHead) -> bool>,
 }
 
 impl fmt::Debug for OriginFn {
@@ -650,7 +655,9 @@ impl Inner {
     }
 
     fn validate_origin_fns(&self, req: &RequestHead) -> bool {
-        self.origins_fns.iter().any(|origin_fn| (origin_fn.f)(req))
+        self.origins_fns
+            .iter()
+            .any(|origin_fn| (origin_fn.boxed_fn)(req))
     }
 
     fn access_control_allow_origin(&self, req: &RequestHead) -> Option<HeaderValue> {
@@ -882,6 +889,7 @@ mod tests {
     use std::convert::Infallible;
 
     use super::*;
+    use regex::bytes::Regex;
 
     #[actix_rt::test]
     async fn allowed_header_tryfrom() {
@@ -1328,6 +1336,56 @@ mod tests {
         }
     }
 
+    #[actix_rt::test]
+    async fn test_allowed_origin_fn_with_environment() {
+        let regex = Regex::new("https:.+\\.unknown\\.com").unwrap();
+        let mut cors = Cors::new()
+            .allowed_origin("https://www.example.com")
+            .allowed_origin_fn(move |req| {
+                req.headers
+                    .get(header::ORIGIN)
+                    .map(HeaderValue::as_bytes)
+                    .filter(|b| regex.is_match(b))
+                    .is_some()
+            })
+            .finish()
+            .new_transform(test::ok_service())
+            .await
+            .unwrap();
+
+        {
+            let req = TestRequest::with_header("Origin", "https://www.example.com")
+                .method(Method::GET)
+                .to_srv_request();
+
+            let resp = test::call_service(&mut cors, req).await;
+
+            assert_eq!(
+                "https://www.example.com",
+                resp.headers()
+                    .get(header::ACCESS_CONTROL_ALLOW_ORIGIN)
+                    .unwrap()
+                    .to_str()
+                    .unwrap()
+            );
+        }
+
+        {
+            let req = TestRequest::with_header("Origin", "https://www.unknown.com")
+                .method(Method::GET)
+                .to_srv_request();
+
+            let resp = test::call_service(&mut cors, req).await;
+
+            assert_eq!(
+                Some(&b"https://www.unknown.com"[..]),
+                resp.headers()
+                    .get(header::ACCESS_CONTROL_ALLOW_ORIGIN)
+                    .map(HeaderValue::as_bytes)
+            );
+        }
+    }
+
     #[actix_rt::test]
     async fn test_not_allowed_origin_fn() {
         let mut cors = Cors::new()