diff --git a/Gopkg.lock b/Gopkg.lock
index 7a83c44..9057360 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -97,21 +97,11 @@
   packages = ["btcec"]
   revision = "e5840949ff4fff0c56f9b6a541e22b63581ea9df"
 
-[[projects]]
-  branch = "master"
-  name = "github.com/tendermint/ed25519"
-  packages = [
-    ".",
-    "edwards25519",
-    "extra25519"
-  ]
-  revision = "d8387025d2b9d158cf4efb07e7ebf814bcce2057"
-
 [[projects]]
   name = "github.com/tendermint/go-amino"
   packages = ["."]
-  revision = "faa6e731944e2b7b6a46ad202902851e8ce85bee"
-  version = "v0.12.0"
+  revision = "dc14acf9ef15f85828bfbc561ed9dd9d2a284885"
+  version = "v0.14.1"
 
 [[projects]]
   name = "github.com/tendermint/tendermint"
@@ -130,22 +120,28 @@
     "libs/pubsub",
     "libs/pubsub/query",
     "types",
-    "types/time"
+    "types/time",
+    "version"
   ]
-  revision = "d419fffe18531317c28c29a292ad7d253f6cafdf"
-  version = "v0.24.0"
+  revision = "44b769b1acd0b2aaa8c199b0885bc2811191fb2e"
+  version = "v0.27.0-dev1"
 
 [[projects]]
-  branch = "master"
   name = "golang.org/x/crypto"
   packages = [
+    "chacha20poly1305",
+    "ed25519",
+    "ed25519/internal/edwards25519",
+    "internal/chacha20",
+    "internal/subtle",
     "pbkdf2",
+    "poly1305",
     "ripemd160"
   ]
-  revision = "0c41d7ab0a0ee717d4590a44bcb987dfd9e183eb"
+  revision = "3764759f34a542a3aef74d6b02e35be7ab893bba"
+  source = "https://github.com/tendermint/crypto"
 
 [[projects]]
-  branch = "release-branch.go1.11"
   name = "golang.org/x/net"
   packages = [
     "context",
@@ -156,7 +152,13 @@
     "internal/timeseries",
     "trace"
   ]
-  revision = "c39426892332e1bb5ec0a434a079bf82f5d30c54"
+  revision = "292b43bbf7cb8d35ddf40f8d5100ef3837cced3f"
+
+[[projects]]
+  branch = "master"
+  name = "golang.org/x/sys"
+  packages = ["cpu"]
+  revision = "4ed8d59d0b35e1e29334a206d1b3f38b1e5dfb31"
 
 [[projects]]
   name = "golang.org/x/text"
@@ -220,6 +222,6 @@
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "67414e714c2545c1a8679288655315fa603e148f48459c727d031bbf164c4d4e"
+  inputs-digest = "51fee76b7596b9a521095252ebf593e08b2b4c3e5584d696d79d290d2dda05d2"
   solver-name = "gps-cdcl"
   solver-version = 1
diff --git a/Gopkg.toml b/Gopkg.toml
index 70ba0fe..e7fde4f 100644
--- a/Gopkg.toml
+++ b/Gopkg.toml
@@ -26,11 +26,12 @@
 
 [[constraint]]
   name = "github.com/tendermint/tendermint"
-  version = "^v0.24.0"
+  version = "^v0.27.0-dev1"
 
 [[override]]
-  name = "golang.org/x/net"
-  branch = "release-branch.go1.11"
+  name = "golang.org/x/crypto"
+  source = "https://github.com/tendermint/crypto"
+  revision = "3764759f34a542a3aef74d6b02e35be7ab893bba"
 
 [[constraint]]
   name = "github.com/certusone/yubihsm-go"
diff --git a/hsm.go b/hsm.go
index bba1e5b..80cc77d 100644
--- a/hsm.go
+++ b/hsm.go
@@ -135,19 +135,6 @@ func (a *AiakosPV) SignProposal(chainID string, proposal *types.Proposal) error
 	return nil
 }
 
-// SignHeartbeat signs a canonical representation of the heartbeat, along with the chainID.
-// Implements PrivValidator.
-func (a *AiakosPV) SignHeartbeat(chainID string, heartbeat *types.Heartbeat) error {
-	signature, err := a.signBytes(heartbeat.SignBytes(chainID))
-	if err != nil {
-		return err
-	}
-
-	heartbeat.Signature = signature
-
-	return nil
-}
-
 // ImportKey imports a Eddsa private key to the specified key slot on the HSM.
 // This fails if the key slot already contains a key.
 // This should be used for testing purposes only. Wrap and import keys in production.