diff --git a/pcap-rewrite/src/filters/dispatch_filter.rs b/pcap-rewrite/src/filters/dispatch_filter.rs
index b257de7..517a712 100644
--- a/pcap-rewrite/src/filters/dispatch_filter.rs
+++ b/pcap-rewrite/src/filters/dispatch_filter.rs
@@ -20,7 +20,8 @@ use crate::filters::key_parser_ipv4;
 use crate::filters::key_parser_ipv6;
 
 /// Function to extract key from data
-pub type GetKeyFn<Key> = Box<dyn Fn(&ParseContext, &[u8]) -> Result<Key, Error>>;
+// pub type GetKeyFn<Key> = Box<dyn Fn(&ParseContext, &[u8]) -> Result<Key, Error>>;
+pub type GetKeyFn<Key> = fn(&ParseContext, &[u8]) -> Result<Key, Error>;
 /// Function to keep/drop extract key from container
 pub type KeepFn<Container, Key> = Box<dyn Fn(&Container, &Key) -> Result<bool, Error>>;
 
@@ -124,8 +125,8 @@ impl DispatchFilterBuilder {
 
                 Ok(Box::new(DispatchFilter::new(
                     ipaddr_container,
-                    Box::new(key_parser_ipv4::parse_src_ipaddr),
-                    Box::new(key_parser_ipv6::parse_src_ipaddr),
+                    key_parser_ipv4::parse_src_ipaddr,
+                    key_parser_ipv6::parse_src_ipaddr,
                     Box::new(keep),
                 )))
             }
@@ -142,8 +143,8 @@ impl DispatchFilterBuilder {
 
                 Ok(Box::new(DispatchFilter::new(
                     ipaddr_container,
-                    Box::new(key_parser_ipv4::parse_dst_ipaddr),
-                    Box::new(key_parser_ipv6::parse_dst_ipaddr),
+                    key_parser_ipv4::parse_dst_ipaddr,
+                    key_parser_ipv6::parse_dst_ipaddr,
                     keep,
                 )))
             }
@@ -162,8 +163,8 @@ impl DispatchFilterBuilder {
 
                 Ok(Box::new(DispatchFilter::new(
                     ipaddr_container,
-                    Box::new(key_parser_ipv4::parse_src_dst_ipaddr),
-                    Box::new(key_parser_ipv6::parse_src_dst_ipaddr),
+                    key_parser_ipv4::parse_src_dst_ipaddr,
+                    key_parser_ipv6::parse_src_dst_ipaddr,
                     keep,
                 )))
             }
@@ -184,8 +185,8 @@ impl DispatchFilterBuilder {
 
                 Ok(Box::new(DispatchFilter::new(
                     ipaddr_proto_port_container,
-                    Box::new(key_parser_ipv4::parse_src_ipaddr_proto_dst_port),
-                    Box::new(key_parser_ipv6::parse_src_ipaddr_proto_dst_port),
+                    key_parser_ipv4::parse_src_ipaddr_proto_dst_port,
+                    key_parser_ipv6::parse_src_ipaddr_proto_dst_port,
                     keep,
                 )))
             }
@@ -200,8 +201,8 @@ impl DispatchFilterBuilder {
 
                 Ok(Box::new(DispatchFilter::new(
                     five_tuple_container,
-                    Box::new(key_parser_ipv4::parse_five_tuple),
-                    Box::new(key_parser_ipv6::parse_five_tuple),
+                    key_parser_ipv4::parse_five_tuple,
+                    key_parser_ipv6::parse_five_tuple,
                     keep,
                 )))
             }
diff --git a/pcap-rewrite/src/filters/filter_utils.rs b/pcap-rewrite/src/filters/filter_utils.rs
index 81c0865..d606043 100644
--- a/pcap-rewrite/src/filters/filter_utils.rs
+++ b/pcap-rewrite/src/filters/filter_utils.rs
@@ -1,15 +1,20 @@
 use log::warn;
 
-use libpcap_tools::{Error,ParseContext};
+use libpcap_tools::{Error, ParseContext};
 use pnet_packet::ethernet::{EtherTypes, EthernetPacket};
 use pnet_packet::vlan::VlanPacket;
 use pnet_packet::Packet;
 use pnet_packet::PrimitiveValues;
 
+/// Function to convert TwoTupleProtoIpid/FiveTuple data to key container
+pub type KeyExtractionFn<D> = fn(&ParseContext, &[u8]) -> Result<D, Error>;
+
 pub fn extract_callback_ethernet<D>(
     ctx: &ParseContext,
-    get_key_from_ipv4_l3_data: &dyn Fn(&ParseContext, &[u8]) -> Result<D, Error>,
-    get_key_from_ipv6_l3_data: &dyn Fn(&ParseContext, &[u8]) -> Result<D, Error>,
+    // get_key_from_ipv4_l3_data: &dyn Fn(&ParseContext, &[u8]) -> Result<D, Error>,
+    // get_key_from_ipv6_l3_data: &dyn Fn(&ParseContext, &[u8]) -> Result<D, Error>,
+    get_key_from_ipv4_l3_data: &KeyExtractionFn<D>,
+    get_key_from_ipv6_l3_data: &KeyExtractionFn<D>,
     packet_data: &[u8],
 ) -> Result<D, Error> {
     let ethernet_packet = EthernetPacket::new(packet_data)
@@ -22,8 +27,8 @@ pub fn extract_callback_ethernet<D>(
             let vlan_packet = VlanPacket::new(ethernet_packet.payload())
                 .ok_or(Error::Pnet("Expected VLAN packet but could not parse"))?;
             match vlan_packet.get_ethertype() {
-                EtherTypes::Ipv4 => (get_key_from_ipv4_l3_data)(ctx,ethernet_packet.payload()),
-                EtherTypes::Ipv6 => (get_key_from_ipv6_l3_data)(ctx,ethernet_packet.payload()),
+                EtherTypes::Ipv4 => (get_key_from_ipv4_l3_data)(ctx, ethernet_packet.payload()),
+                EtherTypes::Ipv6 => (get_key_from_ipv6_l3_data)(ctx, ethernet_packet.payload()),
                 _ => {
                     warn!(
                         "Unimplemented Ethertype in 33024/802.11q: {:?}/{:x}",
diff --git a/pcap-rewrite/src/filters/fragmentation/fragmentation_filter.rs b/pcap-rewrite/src/filters/fragmentation/fragmentation_filter.rs
index 8204191..cb1bfb0 100644
--- a/pcap-rewrite/src/filters/fragmentation/fragmentation_filter.rs
+++ b/pcap-rewrite/src/filters/fragmentation/fragmentation_filter.rs
@@ -29,7 +29,7 @@ use super::convert_fn;
 /// Function to convert TwoTupleProtoIpid/FiveTuple data to key container
 pub type ConvertFn<Container> = Box<dyn Fn(&HashSet<TwoTupleProtoIpidFiveTuple>) -> Container>;
 /// Function to extract key from data
-pub type GetKeyFn<Key> = Box<dyn Fn(&ParseContext, &[u8]) -> Result<Key, Error>>;
+pub type GetKeyFn<Key> = fn(&ParseContext, &[u8]) -> Result<Key, Error>;
 /// Function to keep/drop extract key from container
 pub type KeepFn<Container, Key> = Box<dyn Fn(&Container, &Key) -> Result<bool, Error>>;
 
@@ -151,7 +151,7 @@ impl<Container, Key> FragmentationFilter<Container, Key> {
         ctx: &ParseContext,
         packet_data: PacketData<'j>,
     ) -> FResult<PacketData<'j>, Error> {
-        let key = match packet_data {
+        let key: Key = match packet_data {
             PacketData::L2(data) => {
                 if data.len() < 14 {
                     return Err(Error::DataParser("L2 data too small for ethernet"));
@@ -255,8 +255,8 @@ impl FragmentationFilterBuilder {
                     HashSet::new(),
                     Box::new(convert_fn::convert_data_hs_to_src_ipaddrc),
                     ipaddr_container,
-                    Box::new(key_parser_ipv4::parse_src_ipaddr),
-                    Box::new(key_parser_ipv6::parse_src_ipaddr),
+                    key_parser_ipv4::parse_src_ipaddr,
+                    key_parser_ipv6::parse_src_ipaddr,
                     keep,
                 )))
             }
@@ -274,8 +274,8 @@ impl FragmentationFilterBuilder {
                     HashSet::new(),
                     Box::new(convert_fn::convert_data_hs_to_dst_ipaddrc),
                     ipaddr_container,
-                    Box::new(key_parser_ipv4::parse_dst_ipaddr),
-                    Box::new(key_parser_ipv6::parse_dst_ipaddr),
+                    key_parser_ipv4::parse_dst_ipaddr,
+                    key_parser_ipv6::parse_dst_ipaddr,
                     keep,
                 )))
             }
@@ -295,8 +295,8 @@ impl FragmentationFilterBuilder {
                     HashSet::new(),
                     Box::new(convert_fn::convert_data_hs_to_src_dst_ipaddrc),
                     ipaddr_container,
-                    Box::new(key_parser_ipv4::parse_src_dst_ipaddr),
-                    Box::new(key_parser_ipv6::parse_src_dst_ipaddr),
+                    key_parser_ipv4::parse_src_dst_ipaddr,
+                    key_parser_ipv6::parse_src_dst_ipaddr,
                     keep,
                 )))
             }
@@ -317,8 +317,8 @@ impl FragmentationFilterBuilder {
                     HashSet::new(),
                     Box::new(convert_fn::convert_data_hs_to_src_ipaddr_proto_dst_port_container),
                     ipaddr_proto_port_container,
-                    Box::new(key_parser_ipv4::parse_src_ipaddr_proto_dst_port),
-                    Box::new(key_parser_ipv6::parse_src_ipaddr_proto_dst_port),
+                    key_parser_ipv4::parse_src_ipaddr_proto_dst_port,
+                    key_parser_ipv6::parse_src_ipaddr_proto_dst_port,
                     keep,
                 )))
             }
@@ -347,8 +347,8 @@ impl FragmentationFilterBuilder {
                     HashSet::new(),
                     Box::new(convert_fn::convert_data_hs_to_ctuple),
                     (two_tuple_proto_proto_ipid_c, five_tuple_container),
-                    Box::new(key_parser_ipv4::parse_two_tuple_proto_ipid_five_tuple),
-                    Box::new(key_parser_ipv6::parse_two_tuple_proto_ipid_five_tuple),
+                    key_parser_ipv4::parse_two_tuple_proto_ipid_five_tuple,
+                    key_parser_ipv6::parse_two_tuple_proto_ipid_five_tuple,
                     keep,
                 )))
             }