diff --git a/accounts/keystore/passphrase.go b/accounts/keystore/passphrase.go
index 36c3d0aabc..4a49b41eed 100644
--- a/accounts/keystore/passphrase.go
+++ b/accounts/keystore/passphrase.go
@@ -34,6 +34,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"math"
 	"os"
 	"path/filepath"
 
@@ -385,6 +386,9 @@ func ensureInt(x interface{}) (int, error) {
 	case int:
 		return v, nil
 	case float64:
+		if math.IsNaN(v) || math.IsInf(v, 0) || v != math.Trunc(v) || v < 0 || v > math.MaxInt32 {
+			return 0, fmt.Errorf("invalid KDF parameter: %v", v)
+		}
 		return int(v), nil
 	default:
 		return 0, fmt.Errorf("invalid KDF parameter: expected number, got %T", x)