diff --git a/discord/command.go b/discord/command.go
index 5c77ae5..c2de315 100644
--- a/discord/command.go
+++ b/discord/command.go
@@ -708,3 +708,15 @@ func (m *MentionableOption) MarshalJSON() ([]byte, error) {
 		raw:  (*raw)(m),
 	})
 }
+
+// MarshalJSON marshals NumberOption to JSON with the "type" field.
+func (n *NumberOption) MarshalJSON() ([]byte, error) {
+	type raw NumberOption
+	return json.Marshal(struct {
+		Type CommandOptionType `json:"type"`
+		*raw
+	}{
+		Type: n.Type(),
+		raw:  (*raw)(n),
+	})
+}
diff --git a/utils/generate-option-marshalers.sh b/utils/generate-option-marshalers.sh
index 06cfd54..8b8f168 100755
--- a/utils/generate-option-marshalers.sh
+++ b/utils/generate-option-marshalers.sh
@@ -10,6 +10,7 @@ types=(
 	ChannelOption
 	RoleOption
 	MentionableOption
+	NumberOption
 )
 
 for ((i = 0; i < ${#types[@]}; i++)); {