diff --git a/Cargo.toml b/Cargo.toml
index 4654cdc..ef35ae1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -31,3 +31,4 @@
 insecure = []
 kdf = []
 rand-bytes = []
+experimental-sha512-ec = []
diff --git a/src/public/ec/mod.rs b/src/public/ec/mod.rs
index 9de9ee5..3b8f120 100644
--- a/src/public/ec/mod.rs
+++ b/src/public/ec/mod.rs
@@ -337,6 +337,8 @@
     use std::marker::PhantomData;
 
     use boringssl;
+    #[cfg(feature = "experimental-sha512-ec")]
+    use hash::Sha512;
     use hash::{inner::Digest, Hasher, Sha256, Sha384};
     use public::{
         ec::{EcPrivKey, EcPubKey, PCurve, P256, P384, P521},
@@ -362,6 +364,12 @@
     impl EcdsaHash<P521> for Sha256 {}
     impl EcdsaHash<P521> for Sha384 {}
 
+    #[cfg(feature = "experimental-sha512-ec")]
+    impl EcdsaHash<P384> for Sha512 {}
+
+    #[cfg(feature = "experimental-sha512-ec")]
+    impl EcdsaHash<P521> for Sha512 {}
+
     // The maximum length of an ECDSA signature over P-521. Since this isn't
     // exposed in the API, we can increase later if we add support for curves
     // with larger signatures.
@@ -504,6 +512,19 @@
                 EcdsaSignature::<_, Sha384>::from_bytes,
                 EcdsaSignature::bytes,
             );
+            #[cfg(feature = "experimental-sha512-ec")]
+            {
+                test_signature_smoke(
+                    &p384,
+                    EcdsaSignature::<_, Sha512>::from_bytes,
+                    EcdsaSignature::bytes,
+                );
+                test_signature_smoke(
+                    &p521,
+                    EcdsaSignature::<_, Sha512>::from_bytes,
+                    EcdsaSignature::bytes,
+                );
+            }
         }
 
         #[test]