diff --git a/.github/workflows/jsroot-ci.yml b/.github/workflows/jsroot-ci.yml
index b229f0375..82eb99245 100644
--- a/.github/workflows/jsroot-ci.yml
+++ b/.github/workflows/jsroot-ci.yml
@@ -67,6 +67,7 @@ jobs:
           node demo/node/file_proxy.js buffer ./hsimple.root
           node demo/node/rntuple_buffer_test.js
           node demo/node/rntuple_test.js demo/node/rntuple_test.root
+          node demo/node/tree_int64_test.js demo/node/tree_int64_test.root
           node demo/node/rntuple_test32.js demo/node/rntuple_test32.root demo/node/rntuple_test32.json
 
   tests_ubuntu:
@@ -185,6 +186,7 @@ jobs:
           node demo/node/file_proxy.js buffer ./hsimple.root
           node demo/node/rntuple_buffer_test.js
           node demo/node/rntuple_test.js demo/node/rntuple_test.root
+          node demo/node/tree_int64_test.js demo/node/tree_int64_test.root
           node demo/node/rntuple_test32.js demo/node/rntuple_test32.root demo/node/rntuple_test32.json
 
 
@@ -238,5 +240,6 @@ jobs:
           node demo/node/file_proxy.js buffer ./hsimple.root
           node demo/node/rntuple_buffer_test.js
           node demo/node/rntuple_test.js demo/node/rntuple_test.root
+          node demo/node/tree_int64_test.js demo/node/tree_int64_test.root
           node demo/node/rntuple_test32.js demo/node/rntuple_test32.root demo/node/rntuple_test32.json
 
diff --git a/demo/node/tree_int64_test.cxx b/demo/node/tree_int64_test.cxx
new file mode 100644
index 000000000..a42dba445
--- /dev/null
+++ b/demo/node/tree_int64_test.cxx
@@ -0,0 +1,20 @@
+// macro to create tree_int64_test.root used by tree_int64_test.js
+// root -l -b -q tree_int64_test.cxx
+
+#include <TFile.h>
+#include <TTree.h>
+
+void tree_int64_test()
+{
+   TFile f("tree_int64_test.root", "RECREATE");
+   TTree t("t", "Long64_t values");
+   Long64_t v;
+   t.Branch("v", &v, "v/L");
+   for (Long64_t x : {0LL, 1LL, -1LL, -2LL, -2147483648LL, -4294967296LL, -4294967297LL, -5000000000LL,
+                      -9007199254740991LL, -9007199254740992LL, (Long64_t) 0x8000000000000000ULL,
+                      4294967296LL, 9007199254740991LL, 0x7FFFFFFFFFFFFFFFLL}) {
+      v = x;
+      t.Fill();
+   }
+   t.Write();
+}
diff --git a/demo/node/tree_int64_test.js b/demo/node/tree_int64_test.js
new file mode 100644
index 000000000..bbde113f6
--- /dev/null
+++ b/demo/node/tree_int64_test.js
@@ -0,0 +1,46 @@
+import { version, openFile } from 'jsroot';
+import { TSelector, treeProcess } from 'jsroot/tree';
+
+// check reading of Long64_t branch, file created with tree_int64_test.cxx
+
+console.log(`JSROOT version ${version}`);
+
+const expected = [0n, 1n, -1n, -2n, -2147483648n, -4294967296n, -4294967297n, -5000000000n,
+   -9007199254740991n, -9007199254740992n, -9223372036854775808n,
+   4294967296n, 9007199254740991n, 9223372036854775807n];
+
+let filename = './tree_int64_test.root',
+    any_error = false;
+
+if (process?.argv && process.argv[2])
+   filename = process.argv[2];
+
+const file = await openFile(filename),
+      tree = await file.readObject('t'),
+      values = [],
+      selector = new TSelector();
+
+selector.addBranch('v');
+selector.Process = function() { values.push(this.tgtobj.v); };
+
+await treeProcess(tree, selector);
+
+if (values.length !== expected.length) {
+   any_error = true;
+   console.error(`FAILURE: expected ${expected.length} entries but got ${values.length}`);
+}
+
+expected.forEach((exp, i) => {
+   const val = values[i];
+   if (val === undefined || BigInt(val) !== exp) {
+      any_error = true;
+      console.error(`FAILURE: entry ${i} expected ${exp} but got ${val}`);
+   } else
+      console.log(`OK: entry ${i} = ${val}`);
+});
+
+if (any_error) {
+   console.error('\nFAILURE when reading Long64_t values');
+   process.exit(1);
+} else
+   console.log('\nTest OK');
diff --git a/demo/node/tree_int64_test.root b/demo/node/tree_int64_test.root
new file mode 100644
index 000000000..518292f05
Binary files /dev/null and b/demo/node/tree_int64_test.root differ