diff --git a/pkg/types/state_type.go b/pkg/types/state_type.go
index e2539ba9..1f45686e 100644
--- a/pkg/types/state_type.go
+++ b/pkg/types/state_type.go
@@ -3,8 +3,8 @@ package types
 import (
 	"database/sql/driver"
 	"encoding"
+	"encoding/json"
 	"fmt"
-	"strconv"
 )
 
 // StateType specifies a state's hardness.
@@ -12,21 +12,19 @@ type StateType uint8
 
 // UnmarshalText implements the encoding.TextUnmarshaler interface.
 func (st *StateType) UnmarshalText(bytes []byte) error {
-	text := string(bytes)
+	return st.UnmarshalJSON(bytes)
+}
 
-	i, err := strconv.ParseUint(text, 10, 64)
-	if err != nil {
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (st *StateType) UnmarshalJSON(data []byte) error {
+	var i uint8
+	if err := json.Unmarshal(data, &i); err != nil {
 		return err
 	}
 
 	s := StateType(i)
-	if uint64(s) != i {
-		// Truncated due to above cast, obviously too high
-		return BadStateType{text}
-	}
-
 	if _, ok := stateTypes[s]; !ok {
-		return BadStateType{text}
+		return BadStateType{data}
 	}
 
 	*st = s
@@ -62,5 +60,6 @@ var stateTypes = map[StateType]string{
 var (
 	_ error                    = BadStateType{}
 	_ encoding.TextUnmarshaler = (*StateType)(nil)
+	_ json.Unmarshaler         = (*StateType)(nil)
 	_ driver.Valuer            = StateType(0)
 )