diff --git a/src/env_properties.h b/src/env_properties.h
index fc1772f926e5..8a1fa2daa117 100644
--- a/src/env_properties.h
+++ b/src/env_properties.h
@@ -478,6 +478,7 @@
   V(socketaddress_constructor_template, v8::FunctionTemplate)                  \
   V(space_stats_template, v8::DictionaryTemplate)                              \
   V(sqlite_column_template, v8::DictionaryTemplate)                            \
+  V(sqlite_database_sync_constructor_template, v8::FunctionTemplate)           \
   V(sqlite_limits_template, v8::ObjectTemplate)                                \
   V(sqlite_run_result_template, v8::DictionaryTemplate)                        \
   V(sqlite_statement_sync_constructor_template, v8::FunctionTemplate)          \
diff --git a/src/node_sqlite.cc b/src/node_sqlite.cc
index 76accf1c2731..4ae04615f073 100644
--- a/src/node_sqlite.cc
+++ b/src/node_sqlite.cc
@@ -82,6 +82,23 @@ inline MaybeLocal<String> Utf8StringMaybeOneByte(Isolate* isolate,
       isolate, input.data(), NewStringType::kNormal, len);
 }
 
+static inline void SetSideEffectFreeGetter(
+    Isolate* isolate,
+    Local<FunctionTemplate> class_template,
+    Local<String> name,
+    FunctionCallback fn) {
+  Local<FunctionTemplate> getter =
+      FunctionTemplate::New(isolate,
+                            fn,
+                            Local<Value>(),
+                            v8::Signature::New(isolate, class_template),
+                            /* length */ 0,
+                            ConstructorBehavior::kThrow,
+                            SideEffectType::kHasNoSideEffect);
+  class_template->InstanceTemplate()->SetAccessorProperty(
+      name, getter, Local<FunctionTemplate>(), DontDelete);
+}
+
 BindingData::BindingData(Realm* realm, Local<Object> wrap)
     : BaseObject(realm, wrap) {
   MakeWeak();
@@ -1279,12 +1296,21 @@ std::optional<std::string> ValidateDatabasePath(Environment* env,
   } else if (path->IsObject()) {  // When is URL
     auto url = path.As<Object>();
     Local<Value> href;
-    if (url->Get(env->context(), env->href_string()).ToLocal(&href) &&
-        href->IsString()) {
+    // Let an exception thrown by the href getter propagate instead of
+    // replacing it with ERR_INVALID_ARG_TYPE.
+    if (!url->Get(env->context(), env->href_string()).ToLocal(&href)) {
+      return std::nullopt;
+    }
+    if (href->IsString()) {
       Utf8Value location_value(env->isolate(), href.As<String>());
       auto location = location_value.ToStringView();
       if (!has_null_bytes(location)) {
-        CHECK(ada::can_parse(location));
+        // A real URL always has a parseable href, but any object with a string
+        // href reaches this branch, so the value cannot be assumed to be one.
+        if (!ada::can_parse(location)) {
+          THROW_ERR_INVALID_URL(env->isolate(), "Invalid URL");
+          return std::nullopt;
+        }
         if (!location.starts_with("file:")) {
           THROW_ERR_INVALID_URL_SCHEME(env->isolate());
           return std::nullopt;
@@ -1303,6 +1329,62 @@ std::optional<std::string> ValidateDatabasePath(Environment* env,
   return std::nullopt;
 }
 
+Local<FunctionTemplate> DatabaseSync::GetConstructorTemplate(Environment* env) {
+  Local<FunctionTemplate> tmpl =
+      env->sqlite_database_sync_constructor_template();
+  if (tmpl.IsEmpty()) {
+    Isolate* isolate = env->isolate();
+    tmpl = NewFunctionTemplate(isolate, DatabaseSync::New);
+    tmpl->InstanceTemplate()->SetInternalFieldCount(
+        DatabaseSync::kInternalFieldCount);
+    SetProtoMethod(isolate, tmpl, "open", DatabaseSync::Open);
+    SetProtoMethod(isolate, tmpl, "close", DatabaseSync::Close);
+    SetProtoDispose(isolate, tmpl, DatabaseSync::Dispose);
+    SetProtoMethod(isolate, tmpl, "prepare", DatabaseSync::Prepare);
+    SetProtoMethod(isolate, tmpl, "exec", DatabaseSync::Exec);
+    SetProtoMethod(isolate, tmpl, "function", DatabaseSync::CustomFunction);
+    SetProtoMethod(
+        isolate, tmpl, "createTagStore", DatabaseSync::CreateTagStore);
+    SetProtoMethodNoSideEffect(
+        isolate, tmpl, "location", DatabaseSync::Location);
+    SetProtoMethod(isolate, tmpl, "aggregate", DatabaseSync::AggregateFunction);
+    SetProtoMethod(isolate, tmpl, "createSession", DatabaseSync::CreateSession);
+    SetProtoMethod(
+        isolate, tmpl, "applyChangeset", DatabaseSync::ApplyChangeset);
+    SetProtoMethod(isolate,
+                   tmpl,
+                   "enableLoadExtension",
+                   DatabaseSync::EnableLoadExtension);
+    SetProtoMethod(
+        isolate, tmpl, "enableDefensive", DatabaseSync::EnableDefensive);
+    SetProtoMethod(isolate, tmpl, "loadExtension", DatabaseSync::LoadExtension);
+    SetProtoMethod(isolate, tmpl, "serialize", DatabaseSync::Serialize);
+    SetProtoMethod(isolate, tmpl, "deserialize", DatabaseSync::Deserialize);
+    SetProtoMethod(isolate, tmpl, "setAuthorizer", DatabaseSync::SetAuthorizer);
+    SetSideEffectFreeGetter(isolate,
+                            tmpl,
+                            FIXED_ONE_BYTE_STRING(isolate, "isOpen"),
+                            DatabaseSync::IsOpenGetter);
+    SetSideEffectFreeGetter(isolate,
+                            tmpl,
+                            FIXED_ONE_BYTE_STRING(isolate, "isTransaction"),
+                            DatabaseSync::IsTransactionGetter);
+    SetSideEffectFreeGetter(isolate,
+                            tmpl,
+                            FIXED_ONE_BYTE_STRING(isolate, "limits"),
+                            DatabaseSync::LimitsGetter);
+    Local<String> sqlite_type_key =
+        FIXED_ONE_BYTE_STRING(isolate, "sqlite-type");
+    Local<v8::Symbol> sqlite_type_symbol =
+        v8::Symbol::For(isolate, sqlite_type_key);
+    Local<String> database_sync_string =
+        FIXED_ONE_BYTE_STRING(isolate, "node:sqlite");
+    tmpl->InstanceTemplate()->Set(sqlite_type_symbol, database_sync_string);
+    env->set_sqlite_database_sync_constructor_template(tmpl);
+  }
+  return tmpl;
+}
+
 void DatabaseSync::New(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
   if (!args.IsConstructCall()) {
@@ -2419,9 +2501,13 @@ void DatabaseSync::CreateSession(const FunctionCallbackInfo<Value>& args) {
 
 void Backup(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
-  if (args.Length() < 1 || !args[0]->IsObject()) {
-    THROW_ERR_INVALID_ARG_TYPE(env->isolate(),
-                               "The \"sourceDb\" argument must be an object.");
+  // Unlike the other unwrap sites in this file, which rely on V8's signature
+  // check for args.This(), this one takes a value out of args[] and so has to
+  // check the type itself before unwrapping it.
+  if (!DatabaseSync::GetConstructorTemplate(env)->HasInstance(args[0])) {
+    THROW_ERR_INVALID_ARG_TYPE(
+        env->isolate(),
+        "The \"sourceDb\" argument must be an instance of DatabaseSync.");
     return;
   }
 
@@ -3811,23 +3897,6 @@ SQLTagStore::SQLTagStore(Environment* env,
   MakeWeak();
 }
 
-static inline void SetSideEffectFreeGetter(
-    Isolate* isolate,
-    Local<FunctionTemplate> class_template,
-    Local<String> name,
-    FunctionCallback fn) {
-  Local<FunctionTemplate> getter =
-      FunctionTemplate::New(isolate,
-                            fn,
-                            Local<Value>(),
-                            v8::Signature::New(isolate, class_template),
-                            /* length */ 0,
-                            ConstructorBehavior::kThrow,
-                            SideEffectType::kHasNoSideEffect);
-  class_template->InstanceTemplate()->SetAccessorProperty(
-      name, getter, Local<FunctionTemplate>(), DontDelete);
-}
-
 SQLTagStore::~SQLTagStore() {}
 
 Local<FunctionTemplate> SQLTagStore::GetConstructorTemplate(Environment* env) {
@@ -4569,62 +4638,14 @@ static void Initialize(Local<Object> target,
       }
     });
   }
-  Local<FunctionTemplate> db_tmpl =
-      NewFunctionTemplate(isolate, DatabaseSync::New);
-  db_tmpl->InstanceTemplate()->SetInternalFieldCount(
-      DatabaseSync::kInternalFieldCount);
   Local<Object> constants = Object::New(isolate);
 
   DefineConstants(constants);
 
-  SetProtoMethod(isolate, db_tmpl, "open", DatabaseSync::Open);
-  SetProtoMethod(isolate, db_tmpl, "close", DatabaseSync::Close);
-  SetProtoDispose(isolate, db_tmpl, DatabaseSync::Dispose);
-  SetProtoMethod(isolate, db_tmpl, "prepare", DatabaseSync::Prepare);
-  SetProtoMethod(isolate, db_tmpl, "exec", DatabaseSync::Exec);
-  SetProtoMethod(isolate, db_tmpl, "function", DatabaseSync::CustomFunction);
-  SetProtoMethod(
-      isolate, db_tmpl, "createTagStore", DatabaseSync::CreateTagStore);
-  SetProtoMethodNoSideEffect(
-      isolate, db_tmpl, "location", DatabaseSync::Location);
-  SetProtoMethod(
-      isolate, db_tmpl, "aggregate", DatabaseSync::AggregateFunction);
-  SetProtoMethod(
-      isolate, db_tmpl, "createSession", DatabaseSync::CreateSession);
-  SetProtoMethod(
-      isolate, db_tmpl, "applyChangeset", DatabaseSync::ApplyChangeset);
-  SetProtoMethod(isolate,
-                 db_tmpl,
-                 "enableLoadExtension",
-                 DatabaseSync::EnableLoadExtension);
-  SetProtoMethod(
-      isolate, db_tmpl, "enableDefensive", DatabaseSync::EnableDefensive);
-  SetProtoMethod(
-      isolate, db_tmpl, "loadExtension", DatabaseSync::LoadExtension);
-  SetProtoMethod(isolate, db_tmpl, "serialize", DatabaseSync::Serialize);
-  SetProtoMethod(isolate, db_tmpl, "deserialize", DatabaseSync::Deserialize);
-  SetProtoMethod(
-      isolate, db_tmpl, "setAuthorizer", DatabaseSync::SetAuthorizer);
-  SetSideEffectFreeGetter(isolate,
-                          db_tmpl,
-                          FIXED_ONE_BYTE_STRING(isolate, "isOpen"),
-                          DatabaseSync::IsOpenGetter);
-  SetSideEffectFreeGetter(isolate,
-                          db_tmpl,
-                          FIXED_ONE_BYTE_STRING(isolate, "isTransaction"),
-                          DatabaseSync::IsTransactionGetter);
-  SetSideEffectFreeGetter(isolate,
-                          db_tmpl,
-                          FIXED_ONE_BYTE_STRING(isolate, "limits"),
-                          DatabaseSync::LimitsGetter);
-  Local<String> sqlite_type_key = FIXED_ONE_BYTE_STRING(isolate, "sqlite-type");
-  Local<v8::Symbol> sqlite_type_symbol =
-      v8::Symbol::For(isolate, sqlite_type_key);
-  Local<String> database_sync_string =
-      FIXED_ONE_BYTE_STRING(isolate, "node:sqlite");
-  db_tmpl->InstanceTemplate()->Set(sqlite_type_symbol, database_sync_string);
-
-  SetConstructorFunction(context, target, "DatabaseSync", db_tmpl);
+  SetConstructorFunction(context,
+                         target,
+                         "DatabaseSync",
+                         DatabaseSync::GetConstructorTemplate(env));
   SetConstructorFunction(context,
                          target,
                          "StatementSync",
diff --git a/src/node_sqlite.h b/src/node_sqlite.h
index 306a47f6c47f..a80ec479fac6 100644
--- a/src/node_sqlite.h
+++ b/src/node_sqlite.h
@@ -226,6 +226,8 @@ class DatabaseSync : public BaseObject {
                bool open,
                bool allow_load_extension);
   void MemoryInfo(MemoryTracker* tracker) const override;
+  static v8::Local<v8::FunctionTemplate> GetConstructorTemplate(
+      Environment* env);
   static void New(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void Open(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void IsOpenGetter(const v8::FunctionCallbackInfo<v8::Value>& args);
diff --git a/test/parallel/test-sqlite-backup.mjs b/test/parallel/test-sqlite-backup.mjs
index f995ae3ca72a..6528418eaf65 100644
--- a/test/parallel/test-sqlite-backup.mjs
+++ b/test/parallel/test-sqlite-backup.mjs
@@ -48,10 +48,31 @@ describe('backup()', () => {
       backup();
     }, {
       code: 'ERR_INVALID_ARG_TYPE',
-      message: 'The "sourceDb" argument must be an object.'
+      message: 'The "sourceDb" argument must be an instance of DatabaseSync.'
     });
   });
 
+  test('throws if the source database is not a DatabaseSync', (t) => {
+    const database = makeSourceDb();
+    const values = [
+      {},
+      [],
+      { p0: 1, p1: 2, p2: 3, p3: 4 },
+      { __proto__: DatabaseSync.prototype },
+      database.prepare('SELECT 1'),
+      database.createSession(),
+    ];
+
+    for (const value of values) {
+      t.assert.throws(() => {
+        backup(value, nextDb());
+      }, {
+        code: 'ERR_INVALID_ARG_TYPE',
+        message: 'The "sourceDb" argument must be an instance of DatabaseSync.'
+      });
+    }
+  });
+
   test('throws if path is not a string, URL, or Buffer', (t) => {
     const database = makeSourceDb();
 
@@ -88,6 +109,17 @@ describe('backup()', () => {
     });
   });
 
+  test('throws if the database path has an unparsable href', (t) => {
+    const database = makeSourceDb();
+
+    t.assert.throws(() => {
+      backup(database, { href: 'zzz' });
+    }, {
+      code: 'ERR_INVALID_URL',
+      message: 'Invalid URL'
+    });
+  });
+
   test('throws if options is not an object', (t) => {
     const database = makeSourceDb();
 
diff --git a/test/parallel/test-sqlite-database-sync.js b/test/parallel/test-sqlite-database-sync.js
index 08a636c9cbdc..4e0c7f742f85 100644
--- a/test/parallel/test-sqlite-database-sync.js
+++ b/test/parallel/test-sqlite-database-sync.js
@@ -51,6 +51,24 @@ suite('DatabaseSync() constructor', () => {
     });
   });
 
+  test('throws if the database location has an unparsable href', (t) => {
+    t.assert.throws(() => {
+      new DatabaseSync({ href: 'zzz' });
+    }, {
+      code: 'ERR_INVALID_URL',
+      message: 'Invalid URL',
+    });
+  });
+
+  test('propagates an exception thrown by the href getter', (t) => {
+    t.assert.throws(() => {
+      new DatabaseSync({ get href() { throw new RangeError('boom'); } });
+    }, {
+      name: 'RangeError',
+      message: 'boom',
+    });
+  });
+
   test('throws if options is provided but is not an object', (t) => {
     t.assert.throws(() => {
       new DatabaseSync('foo', null);