diff --git a/query/query.go b/query/query.go
index 24fbd9d..b50f140 100644
--- a/query/query.go
+++ b/query/query.go
@@ -157,6 +157,10 @@ func Fingerprint(q string) string {
 		if Debug {
 			fmt.Printf("\n%d:%d %s/%s [%d:%d] %x %q\n", qi, fi, stateName[s], stateName[sqlState], cpFromOffset, cpToOffset, r, r)
 		}
+		// check `fi` overflow
+		if fi >= len(f) {
+			break
+		}
 
 		/**
 		 * 1. Skip parts of the query for certain states.
diff --git a/query/query_test.go b/query/query_test.go
index df74fb6..840009c 100644
--- a/query/query_test.go
+++ b/query/query_test.go
@@ -635,4 +635,11 @@ func TestFingerprintWithNumberInDbName(t *testing.T) {
 		"select 123foo from 123foo",
 		query.Fingerprint(q),
 	)
+	// fix fi overflow cause index out of range panic
+	q = "insert into tb values(1)"
+	assert.Equal(
+		t,
+		"insert into tb values(?+)",
+		query.Fingerprint(q),
+	)
 }