diff --git a/event.go b/event.go
index 6d3ebb4..ba8b3e3 100644
--- a/event.go
+++ b/event.go
@@ -8,6 +8,8 @@ import (
 	"github.com/mailru/easyjson"
 )
 
+const hextable = "0123456789abcdef"
+
 // Event represents a Nostr event.
 type Event struct {
 	ID        string
@@ -24,7 +26,7 @@ func (evt Event) String() string {
 	return string(j)
 }
 
-// GetID computes the event ID abd returns it as a hex string.
+// GetID computes the event ID and returns it as a hex string.
 func (evt *Event) GetID() string {
 	h := sha256.Sum256(evt.Serialize())
 	return hex.EncodeToString(h[:])
@@ -32,11 +34,13 @@ func (evt *Event) GetID() string {
 
 // CheckID checks if the implied ID matches the given ID more efficiently.
 func (evt *Event) CheckID() bool {
+	if len(evt.ID) != 64 {
+		return false
+	}
+
 	ser := evt.Serialize()
 	h := sha256.Sum256(ser)
 
-	const hextable = "0123456789abcdef"
-
 	for i := 0; i < 32; i++ {
 		b := hextable[h[i]>>4]
 		if b != evt.ID[i*2] {
diff --git a/event_test.go b/event_test.go
index a9453a1..01b882b 100644
--- a/event_test.go
+++ b/event_test.go
@@ -87,6 +87,9 @@ func TestIDCheck(t *testing.T) {
 			Content:   fmt.Sprintf("hello %d", i),
 			Tags:      Tags{},
 		}
+
+		require.False(t, evt.CheckID())
+
 		evt.Sign(GeneratePrivateKey())
 		require.True(t, evt.CheckID())