diff --git a/src/headerdef.rs b/src/headerdef.rs
index 879dfc1e1..0bf70caf5 100644
--- a/src/headerdef.rs
+++ b/src/headerdef.rs
@@ -1,4 +1,6 @@
-#[derive(Debug, Display, Clone, PartialEq, Eq, EnumVariantNames)]
+use crate::strum::AsStaticRef;
+
+#[derive(Debug, Display, Clone, PartialEq, Eq, EnumVariantNames, AsStaticStr)]
 #[strum(serialize_all = "kebab_case")]
 #[allow(dead_code)]
 pub enum HeaderDef {
@@ -43,8 +45,8 @@ pub enum HeaderDef {
 
 impl HeaderDef {
     /// Returns the corresponding Event id.
-    pub fn get_headername(&self) -> String {
-        self.to_string()
+    pub fn get_headername(&self) -> &'static str {
+        self.as_static()
     }
 }
 
@@ -55,8 +57,8 @@ mod tests {
     #[test]
     /// Test that kebab_case serialization works as expected
     fn kebab_test() {
-        assert_eq!(HeaderDef::From_.to_string(), "from");
+        assert_eq!(HeaderDef::From_.get_headername(), "from");
 
-        assert_eq!(HeaderDef::_TestHeader.to_string(), "test-header");
+        assert_eq!(HeaderDef::_TestHeader.get_headername(), "test-header");
     }
 }
diff --git a/src/mimeparser.rs b/src/mimeparser.rs
index c94ea6b57..5e733a667 100644
--- a/src/mimeparser.rs
+++ b/src/mimeparser.rs
@@ -402,7 +402,7 @@ impl MimeMessage {
     }
 
     pub fn get(&self, headerdef: HeaderDef) -> Option<&String> {
-        self.header.get(&headerdef.get_headername())
+        self.header.get(headerdef.get_headername())
     }
 
     fn parse_first_addr(&self, context: &Context, headerdef: HeaderDef) -> Option<MailAddr> {