diff --git a/cmd/abidump/main.go b/cmd/abidump/main.go
new file mode 100644
index 000000000..35cbcbb0e
--- /dev/null
+++ b/cmd/abidump/main.go
@@ -0,0 +1,74 @@
+// Copyright 2019 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"encoding/hex"
+	"flag"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/signer/core"
+	"github.com/ethereum/go-ethereum/signer/fourbyte"
+)
+
+func init() {
+	flag.Usage = func() {
+		fmt.Fprintln(os.Stderr, "Usage:", os.Args[0], "<hexdata>")
+		flag.PrintDefaults()
+		fmt.Fprintln(os.Stderr, `
+Parses the given ABI data and tries to interpret it from the fourbyte database.`)
+	}
+}
+
+func parse(data []byte) {
+	db, err := fourbyte.New()
+	if err != nil {
+		die(err)
+	}
+	messages := core.ValidationMessages{}
+	db.ValidateCallData(nil, data, &messages)
+	for _, m := range messages.Messages {
+		fmt.Printf("%v: %v\n", m.Typ, m.Message)
+	}
+}
+
+// Example
+// ./abidump a9059cbb000000000000000000000000ea0e2dc7d65a50e77fc7e84bff3fd2a9e781ff5c0000000000000000000000000000000000000000000000015af1d78b58c40000
+func main() {
+	flag.Parse()
+
+	switch {
+	case flag.NArg() == 1:
+		hexdata := flag.Arg(0)
+		data, err := hex.DecodeString(strings.TrimPrefix(hexdata, "0x"))
+		if err != nil {
+			die(err)
+		}
+		parse(data)
+	default:
+		fmt.Fprintln(os.Stderr, "Error: one argument needed")
+		flag.Usage()
+		os.Exit(2)
+	}
+}
+
+func die(args ...interface{}) {
+	fmt.Fprintln(os.Stderr, args...)
+	os.Exit(1)
+}
diff --git a/signer/fourbyte/abi.go b/signer/fourbyte/abi.go
index 585eae1cd..796086d41 100644
--- a/signer/fourbyte/abi.go
+++ b/signer/fourbyte/abi.go
@@ -137,7 +137,7 @@ func parseCallData(calldata []byte, abidata string) (*decodedCallData, error) {
 	}
 	values, err := method.Inputs.UnpackValues(argdata)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("signature %q matches, but arguments mismatch: %v", method.String(), err)
 	}
 	// Everything valid, assemble the call infos for the signer
 	decoded := decodedCallData{signature: method.Sig(), name: method.RawName}
diff --git a/signer/fourbyte/validation.go b/signer/fourbyte/validation.go
index 4d042d240..fd13e0a63 100644
--- a/signer/fourbyte/validation.go
+++ b/signer/fourbyte/validation.go
@@ -74,13 +74,13 @@ func (db *Database) ValidateTransaction(selector *string, tx *core.SendTxArgs) (
 		messages.Crit("Transaction recipient is the zero address")
 	}
 	// Semantic fields validated, try to make heads or tails of the call data
-	db.validateCallData(selector, data, messages)
+	db.ValidateCallData(selector, data, messages)
 	return messages, nil
 }
 
-// validateCallData checks if the ABI call-data + method selector (if given) can
+// ValidateCallData checks if the ABI call-data + method selector (if given) can
 // be parsed and seems to match.
-func (db *Database) validateCallData(selector *string, data []byte, messages *core.ValidationMessages) {
+func (db *Database) ValidateCallData(selector *string, data []byte, messages *core.ValidationMessages) {
 	// If the data is empty, we have a plain value transfer, nothing more to do
 	if len(data) == 0 {
 		return
@@ -110,7 +110,7 @@ func (db *Database) validateCallData(selector *string, data []byte, messages *co
 		return
 	}
 	if info, err := verifySelector(embedded, data); err != nil {
-		messages.Warn(fmt.Sprintf("Transaction contains data, but provided ABI signature could not be varified: %v", err))
+		messages.Warn(fmt.Sprintf("Transaction contains data, but provided ABI signature could not be verified: %v", err))
 	} else {
 		messages.Info(info.String())
 	}