diff --git a/CHANGELOG_PENDING.md b/CHANGELOG_PENDING.md
index c8bb7bcca..3ab1632e3 100644
--- a/CHANGELOG_PENDING.md
+++ b/CHANGELOG_PENDING.md
@@ -20,6 +20,7 @@ program](https://hackerone.com/tendermint).
 ### IMPROVEMENTS:
 
 - [rpc] \#2010 Add NewHTTPWithClient and NewJSONRPCClientWithHTTPClient (note these and NewHTTP, NewJSONRPCClient functions panic if remote is invalid) (@gracenoah)
+- [rpc] \#3984 Add `MempoolClient` interface to `Client` interface
 
 ### BUG FIXES:
 
diff --git a/rpc/client/interface.go b/rpc/client/interface.go
index 383e0b480..c4a7b023d 100644
--- a/rpc/client/interface.go
+++ b/rpc/client/interface.go
@@ -39,6 +39,7 @@ type Client interface {
 	SignClient
 	StatusClient
 	EvidenceClient
+	MempoolClient
 }
 
 // ABCIClient groups together the functionality that principally affects the
diff --git a/rpc/client/mock/client.go b/rpc/client/mock/client.go
index 3ec40d6cc..b7fdd602d 100644
--- a/rpc/client/mock/client.go
+++ b/rpc/client/mock/client.go
@@ -37,6 +37,7 @@ type Client struct {
 	client.StatusClient
 	client.EventsClient
 	client.EvidenceClient
+	client.MempoolClient
 	cmn.Service
 }
 
diff --git a/types/vote.go b/types/vote.go
index 69cc514bd..8f5eee7fb 100644
--- a/types/vote.go
+++ b/types/vote.go
@@ -12,8 +12,8 @@ import (
 
 const (
 	// MaxVoteBytes is a maximum vote size (including amino overhead).
-	MaxVoteBytes int64 = 223
-	nilVoteStr         = "nil-Vote"
+	MaxVoteBytes int64  = 223
+	nilVoteStr   string = "nil-Vote"
 )
 
 var (