diff --git a/src/content_blocking.rs b/src/content_blocking.rs
index 128d202f..77b12f9b 100644
--- a/src/content_blocking.rs
+++ b/src/content_blocking.rs
@@ -464,7 +464,9 @@ impl TryFrom<NetworkFilter> for CbRuleEquivalent {
                     } else {
                         // The network filter has already parsed successfully, so this should be
                         // safe
-                        idna::domain_to_ascii(&lowercase).unwrap()
+                        idna::domain_to_ascii_cow(&lowercase.as_bytes(), idna::AsciiDenyList::EMPTY)
+                            .unwrap()
+                            .to_string()
                     };
 
                     collection.push(format!("*{normalized_domain}"));
@@ -616,13 +618,19 @@ impl TryFrom<CosmeticFilter> for CbRule {
                         any_unsupported = true
                     }
                     LocationType::Hostname => {
-                        if let Ok(encoded) = idna::domain_to_ascii(location) {
-                            hostnames_vec.push(encoded);
+                        if let Ok(encoded) = idna::domain_to_ascii_cow(
+                            location.as_bytes(),
+                            idna::AsciiDenyList::EMPTY,
+                        ) {
+                            hostnames_vec.push(encoded.to_string());
                         }
                     }
                     LocationType::NotHostname => {
-                        if let Ok(encoded) = idna::domain_to_ascii(location) {
-                            not_hostnames_vec.push(encoded);
+                        if let Ok(encoded) = idna::domain_to_ascii_cow(
+                            location.as_bytes(),
+                            idna::AsciiDenyList::EMPTY,
+                        ) {
+                            not_hostnames_vec.push(encoded.to_string());
                         }
                     }
                 },
diff --git a/src/filters/cosmetic.rs b/src/filters/cosmetic.rs
index 37ea8970..811b4351 100644
--- a/src/filters/cosmetic.rs
+++ b/src/filters/cosmetic.rs
@@ -228,7 +228,7 @@ impl CosmeticFilter {
             if location.is_ascii() {
                 hostname.push_str(location);
             } else {
-                match idna::domain_to_ascii(location) {
+                match idna::domain_to_ascii_cow(location.as_bytes(), idna::AsciiDenyList::EMPTY) {
                     Ok(x) if !x.is_empty() => hostname.push_str(&x),
                     _ => return Err(CosmeticFilterError::PunycodeError),
                 }
diff --git a/src/url_parser/parser.rs b/src/url_parser/parser.rs
index 66bcd485..3308352f 100644
--- a/src/url_parser/parser.rs
+++ b/src/url_parser/parser.rs
@@ -531,7 +531,8 @@ impl Parser {
         if host_str.is_ascii() {
             write!(&mut self.serialization, "{host_str}").unwrap();
         } else {
-            let encoded = idna::domain_to_ascii(host_str)?;
+            let encoded =
+                idna::domain_to_ascii_cow(host_str.as_bytes(), idna::AsciiDenyList::EMPTY)?;
             write!(&mut self.serialization, "{encoded}").unwrap();
         }