diff --git a/Makefile b/Makefile
index d487e496..ae303266 100644
--- a/Makefile
+++ b/Makefile
@@ -37,7 +37,8 @@ EMFLAGS = \
 	-s EXPORTED_RUNTIME_METHODS=@src/exported_runtime_methods.json \
 	-s SINGLE_FILE=0 \
 	-s NODEJS_CATCH_EXIT=0 \
-	-s NODEJS_CATCH_REJECTION=0
+	-s NODEJS_CATCH_REJECTION=0 \
+	-s STACK_SIZE=5MB
 
 EMFLAGS_ASM = \
 	-s WASM=0
@@ -56,7 +57,7 @@ EMFLAGS_OPTIMIZED= \
 	--closure 1
 
 EMFLAGS_DEBUG = \
-	-s ASSERTIONS=1 \
+	-s ASSERTIONS=2 \
 	-O1
 
 BITCODE_FILES = out/sqlite3.bc out/extension-functions.bc
diff --git a/test/test_long_sql_statement.js b/test/test_long_sql_statement.js
new file mode 100644
index 00000000..3005c087
--- /dev/null
+++ b/test/test_long_sql_statement.js
@@ -0,0 +1,34 @@
+// test for https://github.com/sql-js/sql.js/issues/561
+exports.test = function (sql, assert) {
+    // Create a database
+    var db = new sql.Database();
+    var len = 70000;
+    var many_a = "";
+    for (var i = 0; i < len; i++) many_a += 'a';
+
+    var res = db.exec("select length('" + many_a + "') as len");
+    var expectedResult = [
+        {
+            columns: ['len'],
+            values: [
+                [len]
+            ]
+        }
+    ];
+    assert.deepEqual(res, expectedResult, "length of long string");
+};
+
+if (module == require.main) {
+    const target_file = process.argv[2];
+    const sql_loader = require('./load_sql_lib');
+    sql_loader(target_file).then((sql) => {
+        require('test').run({
+            'test long sql string (issue 561)': function (assert) {
+                exports.test(sql, assert);
+            }
+        });
+    }).catch((e) => {
+        console.error(e);
+        assert.fail(e);
+    });
+}