diff --git a/compiler/rustc_data_structures/src/fingerprint.rs b/compiler/rustc_data_structures/src/fingerprint.rs
index 6b533f9f05790..81b115fac0d0e 100644
--- a/compiler/rustc_data_structures/src/fingerprint.rs
+++ b/compiler/rustc_data_structures/src/fingerprint.rs
@@ -1,8 +1,5 @@
 use crate::stable_hasher;
-use rustc_serialize::{
-    opaque::{self, EncodeResult, FileEncodeResult},
-    Decodable, Decoder, Encodable, Encoder,
-};
+use rustc_serialize::{Decodable, Encodable};
 use std::hash::{Hash, Hasher};
 use std::mem::{self, MaybeUninit};
 
@@ -63,16 +60,6 @@ impl Fingerprint {
     pub fn to_hex(&self) -> String {
         format!("{:x}{:x}", self.0, self.1)
     }
-
-    pub fn decode_opaque(decoder: &mut opaque::Decoder<'_>) -> Result<Fingerprint, String> {
-        let mut bytes: [MaybeUninit<u8>; 16] = MaybeUninit::uninit_array();
-
-        decoder.read_raw_bytes(&mut bytes)?;
-
-        let [l, r]: [u64; 2] = unsafe { mem::transmute(bytes) };
-
-        Ok(Fingerprint(u64::from_le(l), u64::from_le(r)))
-    }
 }
 
 impl std::fmt::Display for Fingerprint {
@@ -130,55 +117,22 @@ impl stable_hasher::StableHasherResult for Fingerprint {
 impl_stable_hash_via_hash!(Fingerprint);
 
 impl<E: rustc_serialize::Encoder> Encodable<E> for Fingerprint {
+    #[inline]
     fn encode(&self, s: &mut E) -> Result<(), E::Error> {
-        s.encode_fingerprint(self)
+        let bytes: [u8; 16] = unsafe { mem::transmute([self.0.to_le(), self.1.to_le()]) };
+        s.emit_raw_bytes(&bytes)?;
+        Ok(())
     }
 }
 
 impl<D: rustc_serialize::Decoder> Decodable<D> for Fingerprint {
+    #[inline]
     fn decode(d: &mut D) -> Result<Self, D::Error> {
-        d.decode_fingerprint()
-    }
-}
-
-pub trait FingerprintEncoder: rustc_serialize::Encoder {
-    fn encode_fingerprint(&mut self, f: &Fingerprint) -> Result<(), Self::Error>;
-}
-
-pub trait FingerprintDecoder: rustc_serialize::Decoder {
-    fn decode_fingerprint(&mut self) -> Result<Fingerprint, Self::Error>;
-}
-
-impl<E: rustc_serialize::Encoder> FingerprintEncoder for E {
-    default fn encode_fingerprint(&mut self, _: &Fingerprint) -> Result<(), E::Error> {
-        panic!("Cannot encode `Fingerprint` with `{}`", std::any::type_name::<E>());
-    }
-}
-
-impl FingerprintEncoder for opaque::Encoder {
-    fn encode_fingerprint(&mut self, f: &Fingerprint) -> EncodeResult {
-        let bytes: [u8; 16] = unsafe { mem::transmute([f.0.to_le(), f.1.to_le()]) };
-        self.emit_raw_bytes(&bytes)?;
-        Ok(())
-    }
-}
-
-impl FingerprintEncoder for opaque::FileEncoder {
-    fn encode_fingerprint(&mut self, f: &Fingerprint) -> FileEncodeResult {
-        let bytes: [u8; 16] = unsafe { mem::transmute([f.0.to_le(), f.1.to_le()]) };
-        self.emit_raw_bytes(&bytes)
-    }
-}
-
-impl<D: rustc_serialize::Decoder> FingerprintDecoder for D {
-    default fn decode_fingerprint(&mut self) -> Result<Fingerprint, D::Error> {
-        panic!("Cannot decode `Fingerprint` with `{}`", std::any::type_name::<D>());
-    }
-}
+        let mut bytes: [MaybeUninit<u8>; 16] = MaybeUninit::uninit_array();
+        d.read_raw_bytes(&mut bytes)?;
 
-impl FingerprintDecoder for opaque::Decoder<'_> {
-    fn decode_fingerprint(&mut self) -> Result<Fingerprint, String> {
-        Fingerprint::decode_opaque(self)
+        let [l, r]: [u64; 2] = unsafe { mem::transmute(bytes) };
+        Ok(Fingerprint(u64::from_le(l), u64::from_le(r)))
     }
 }
 
diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index e9b8388c1c915..e8891e471f9da 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -7,7 +7,6 @@ use crate::rmeta::*;
 use rustc_ast as ast;
 use rustc_attr as attr;
 use rustc_data_structures::captures::Captures;
-use rustc_data_structures::fingerprint::{Fingerprint, FingerprintDecoder};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::{Lock, LockGuard, Lrc, OnceCell};
@@ -351,12 +350,6 @@ impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for DefIndex {
     }
 }
 
-impl<'a, 'tcx> FingerprintDecoder for DecodeContext<'a, 'tcx> {
-    fn decode_fingerprint(&mut self) -> Result<Fingerprint, String> {
-        Fingerprint::decode_opaque(&mut self.opaque)
-    }
-}
-
 impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for SyntaxContext {
     fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Result<SyntaxContext, String> {
         let cdata = decoder.cdata();
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index a07e0476050da..09b9ceb990186 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -1,7 +1,6 @@
 use crate::rmeta::table::{FixedSizeEncoding, TableBuilder};
 use crate::rmeta::*;
 
-use rustc_data_structures::fingerprint::{Fingerprint, FingerprintEncoder};
 use rustc_data_structures::fx::{FxHashMap, FxIndexSet};
 use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_data_structures::sync::{join, par_iter, Lrc, ParallelIterator};
@@ -308,12 +307,6 @@ impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for Span {
     }
 }
 
-impl<'a, 'tcx> FingerprintEncoder for EncodeContext<'a, 'tcx> {
-    fn encode_fingerprint(&mut self, f: &Fingerprint) -> Result<(), Self::Error> {
-        self.opaque.encode_fingerprint(f)
-    }
-}
-
 impl<'a, 'tcx> TyEncoder<'tcx> for EncodeContext<'a, 'tcx> {
     const CLEAR_CROSS_CRATE: bool = true;
 
diff --git a/compiler/rustc_middle/src/ty/query/on_disk_cache.rs b/compiler/rustc_middle/src/ty/query/on_disk_cache.rs
index e4c5907f5a593..ff11314d2ffd1 100644
--- a/compiler/rustc_middle/src/ty/query/on_disk_cache.rs
+++ b/compiler/rustc_middle/src/ty/query/on_disk_cache.rs
@@ -4,7 +4,6 @@ use crate::mir::{self, interpret};
 use crate::ty::codec::{RefDecodable, TyDecoder, TyEncoder};
 use crate::ty::context::TyCtxt;
 use crate::ty::{self, Ty};
-use rustc_data_structures::fingerprint::{Fingerprint, FingerprintDecoder, FingerprintEncoder};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
 use rustc_data_structures::sync::{HashMapExt, Lock, Lrc, OnceCell};
 use rustc_data_structures::thin_vec::ThinVec;
@@ -913,12 +912,6 @@ impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for DefId {
     }
 }
 
-impl<'a, 'tcx> FingerprintDecoder for CacheDecoder<'a, 'tcx> {
-    fn decode_fingerprint(&mut self) -> Result<Fingerprint, Self::Error> {
-        Fingerprint::decode_opaque(&mut self.opaque)
-    }
-}
-
 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for &'tcx FxHashSet<LocalDefId> {
     fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
         RefDecodable::decode(d)
@@ -1011,12 +1004,6 @@ where
     }
 }
 
-impl<'a, 'tcx, E: OpaqueEncoder> FingerprintEncoder for CacheEncoder<'a, 'tcx, E> {
-    fn encode_fingerprint(&mut self, f: &Fingerprint) -> Result<(), E::Error> {
-        self.encoder.encode_fingerprint(f)
-    }
-}
-
 impl<'a, 'tcx, E> Encodable<CacheEncoder<'a, 'tcx, E>> for SyntaxContext
 where
     E: 'a + OpaqueEncoder,