diff --git a/minidom-rs/src/element.rs b/minidom-rs/src/element.rs
index 9041166..fdd4dd1 100644
--- a/minidom-rs/src/element.rs
+++ b/minidom-rs/src/element.rs
@@ -1093,7 +1093,7 @@ mod tests {
         assert_eq!(elem.name(), String::from("bar"));
         assert_eq!(elem.ns(), String::from("ns1"));
         // Ensure the prefix is properly added to the store
-        assert_eq!(elem.prefixes.get(Some(String::from("foo"))), Some(&String::from("ns1")));
+        assert_eq!(elem.prefixes.get(&Some(String::from("foo"))), Some(&String::from("ns1")));
     }
 
     #[test]
diff --git a/minidom-rs/src/prefixes.rs b/minidom-rs/src/prefixes.rs
index e6bb0d5..0406e2b 100644
--- a/minidom-rs/src/prefixes.rs
+++ b/minidom-rs/src/prefixes.rs
@@ -49,8 +49,8 @@ impl Prefixes {
         &self.prefixes
     }
 
-    pub fn get(&self, prefix: Prefix) -> Option<&Namespace> {
-        self.prefixes.get(&prefix)
+    pub fn get(&self, prefix: &Prefix) -> Option<&Namespace> {
+        self.prefixes.get(prefix)
     }
 
     pub(crate) fn insert<S: Into<Namespace>>(&mut self, prefix: Prefix, namespace: S) {