diff --git a/ext/hash/hash.go b/ext/hash/hash.go
index 4ee9cc1..c9c3cd9 100644
--- a/ext/hash/hash.go
+++ b/ext/hash/hash.go
@@ -29,7 +29,7 @@ import (
 
 // Register registers cryptographic hash functions for a database connection.
 func Register(db *sqlite3.Conn) error {
-	flags := sqlite3.DETERMINISTIC | sqlite3.INNOCUOUS
+	const flags = sqlite3.DETERMINISTIC | sqlite3.INNOCUOUS
 
 	var errs util.ErrorJoiner
 	if crypto.MD4.Available() {
diff --git a/ext/regexp/regexp.go b/ext/regexp/regexp.go
index 6b8ce35..8253c53 100644
--- a/ext/regexp/regexp.go
+++ b/ext/regexp/regexp.go
@@ -20,7 +20,7 @@ import (
 
 // Register registers Unicode aware functions for a database connection.
 func Register(db *sqlite3.Conn) error {
-	flags := sqlite3.DETERMINISTIC | sqlite3.INNOCUOUS
+	const flags = sqlite3.DETERMINISTIC | sqlite3.INNOCUOUS
 	return errors.Join(
 		db.CreateFunction("regexp", 2, flags, regex),
 		db.CreateFunction("regexp_like", 2, flags, regexLike),
diff --git a/ext/stats/stats.go b/ext/stats/stats.go
index 69371c4..f16423d 100644
--- a/ext/stats/stats.go
+++ b/ext/stats/stats.go
@@ -52,7 +52,7 @@ import (
 
 // Register registers statistics functions.
 func Register(db *sqlite3.Conn) error {
-	flags := sqlite3.DETERMINISTIC | sqlite3.INNOCUOUS
+	const flags = sqlite3.DETERMINISTIC | sqlite3.INNOCUOUS
 	return errors.Join(
 		db.CreateWindowFunction("var_pop", 1, flags, newVariance(var_pop)),
 		db.CreateWindowFunction("var_samp", 1, flags, newVariance(var_samp)),
diff --git a/ext/unicode/unicode.go b/ext/unicode/unicode.go
index 1e8989e..3620cee 100644
--- a/ext/unicode/unicode.go
+++ b/ext/unicode/unicode.go
@@ -38,12 +38,22 @@ import (
 	"golang.org/x/text/unicode/norm"
 )
 
+// Set RegisterLike to false to not register a Unicode aware LIKE operator.
+// Overriding the built-in LIKE operator disables the [LIKE optimization].
+//
+// [LIKE optimization]: https://sqlite.org/optoverview.html#the_like_optimization
+var RegisterLike = true
+
 // Register registers Unicode aware functions for a database connection.
 func Register(db *sqlite3.Conn) error {
-	flags := sqlite3.DETERMINISTIC | sqlite3.INNOCUOUS
-	return errors.Join(
-		db.CreateFunction("like", 2, flags, like),
-		db.CreateFunction("like", 3, flags, like),
+	const flags = sqlite3.DETERMINISTIC | sqlite3.INNOCUOUS
+	var errs util.ErrorJoiner
+	if RegisterLike {
+		errs.Join(
+			db.CreateFunction("like", 2, flags, like),
+			db.CreateFunction("like", 3, flags, like))
+	}
+	errs.Join(
 		db.CreateFunction("upper", 1, flags, upper),
 		db.CreateFunction("upper", 2, flags, upper),
 		db.CreateFunction("lower", 1, flags, lower),
@@ -59,12 +69,13 @@ func Register(db *sqlite3.Conn) error {
 					return
 				}
 
-				err := RegisterCollation(db, arg[0].Text(), name)
+				err := RegisterCollation(ctx.Conn(), arg[0].Text(), name)
 				if err != nil {
 					ctx.ResultError(err)
 					return // notest
 				}
 			}))
+	return errors.Join(errs...)
 }
 
 // RegisterCollation registers a Unicode collation sequence for a database connection.
@@ -146,7 +157,7 @@ func unaccent(ctx sqlite3.Context, arg ...sqlite3.Value) {
 	unaccent := transform.Chain(norm.NFD, runes.Remove(runes.In(unicode.Mn)), norm.NFC)
 	res, _, err := transform.Bytes(unaccent, arg[0].RawText())
 	if err != nil {
-		ctx.ResultError(err)
+		ctx.ResultError(err) // notest
 	} else {
 		ctx.ResultRawText(res)
 	}
diff --git a/ext/uuid/uuid.go b/ext/uuid/uuid.go
index 05bb12d..2febdef 100644
--- a/ext/uuid/uuid.go
+++ b/ext/uuid/uuid.go
@@ -27,7 +27,7 @@ import (
 //
 // Converts a UUID into a 16-byte blob.
 func Register(db *sqlite3.Conn) error {
-	flags := sqlite3.DETERMINISTIC | sqlite3.INNOCUOUS
+	const flags = sqlite3.DETERMINISTIC | sqlite3.INNOCUOUS
 	return errors.Join(
 		db.CreateFunction("uuid", 0, sqlite3.INNOCUOUS, generate),
 		db.CreateFunction("uuid", 1, sqlite3.INNOCUOUS, generate),
diff --git a/ext/zorder/zorder.go b/ext/zorder/zorder.go
index be5a290..627b632 100644
--- a/ext/zorder/zorder.go
+++ b/ext/zorder/zorder.go
@@ -12,7 +12,7 @@ import (
 
 // Register registers the zorder and unzorder SQL functions.
 func Register(db *sqlite3.Conn) error {
-	flags := sqlite3.DETERMINISTIC | sqlite3.INNOCUOUS
+	const flags = sqlite3.DETERMINISTIC | sqlite3.INNOCUOUS
 	return errors.Join(
 		db.CreateFunction("zorder", -1, flags, zorder),
 		db.CreateFunction("unzorder", 3, flags, unzorder))