diff --git a/LiteCore/Storage/UnicodeCollator_Stub.cc b/LiteCore/Storage/UnicodeCollator_Stub.cc
index 0dc88dca65..e41dad8273 100644
--- a/LiteCore/Storage/UnicodeCollator_Stub.cc
+++ b/LiteCore/Storage/UnicodeCollator_Stub.cc
@@ -19,9 +19,9 @@ namespace litecore {
 
     using namespace std;
 
-    int CompareUTF8(slice str1, slice str2, const CollationContext&) { error::_throw(error::Unimplemented); }
+    int CompareUTF8(fleece::slice str1, fleece::slice str2, const CollationContext&) { error::_throw(error::Unimplemented); }
 
-    bool ContainsUTF8(slice str, slice substr, const CollationContext&) { error::_throw(error::Unimplemented); }
+    bool ContainsUTF8(fleece::slice str, fleece::slice substr, const CollationContext&) { error::_throw(error::Unimplemented); }
 
     unique_ptr<CollationContext> RegisterSQLiteUnicodeCollation(sqlite3* dbHandle, const Collation& coll) {
         return nullptr;