diff --git a/javascript/ql/test/library-tests/Constants/Constants.expected b/javascript/ql/test/library-tests/Constants/Constants.expected
index 75a63830277..35ce0fc93ff 100644
--- a/javascript/ql/test/library-tests/Constants/Constants.expected
+++ b/javascript/ql/test/library-tests/Constants/Constants.expected
@@ -1,3 +1,33 @@
+getIntValue
+| tst2.ts:1:21:1:21 | 1 | 1 |
+| tst.js:6:1:6:1 | 1 | 1 |
+| tst.js:11:1:11:2 | -1 | -1 |
+| tst.js:11:2:11:2 | 1 | 1 |
+| tst.js:12:2:12:2 | 0 | 0 |
+| tst.js:26:3:26:3 | 0 | 0 |
+| tst.js:29:6:29:6 | 0 | 0 |
+| tst.js:35:1:35:1 | 1 | 1 |
+| tst.js:35:5:35:5 | 2 | 2 |
+| tst.js:35:9:35:9 | 3 | 3 |
+| tst.js:37:1:37:3 | (1) | 1 |
+| tst.js:37:2:37:2 | 1 | 1 |
+| tst.js:39:4:39:4 | 1 | 1 |
+| tst.js:40:1:40:1 | 1 | 1 |
+| tst.js:42:1:42:1 | 1 | 1 |
+| tst.js:42:4:42:4 | 2 | 2 |
+| tst.js:42:7:42:7 | 3 | 3 |
+| tst.js:43:4:43:4 | 2 | 2 |
+| tst.js:43:7:43:7 | 3 | 3 |
+| tst.js:44:1:44:1 | 1 | 1 |
+| tst.js:44:7:44:7 | 3 | 3 |
+| tst.js:45:1:45:1 | 1 | 1 |
+| tst.js:45:4:45:4 | 2 | 2 |
+| tst.js:47:5:47:5 | 1 | 1 |
+| tst.js:48:7:48:7 | 1 | 1 |
+| tst.js:49:6:49:6 | 1 | 1 |
+| tst.js:52:5:52:9 | 1_000 | 1 |
+| tst.js:53:5:53:13 | 1_000_123 | 1 |
+#select
 | tst2.ts:1:13:1:21 | <number>1 |
 | tst2.ts:1:21:1:21 | 1 |
 | tst.js:1:1:1:3 | "a" |
@@ -61,3 +91,7 @@
 | tst.js:48:1:48:7 | x.p = 1 |
 | tst.js:48:7:48:7 | 1 |
 | tst.js:49:6:49:6 | 1 |
+| tst.js:52:1:52:9 | x = 1_000 |
+| tst.js:52:5:52:9 | 1_000 |
+| tst.js:53:1:53:13 | x = 1_000_123 |
+| tst.js:53:5:53:13 | 1_000_123 |
diff --git a/javascript/ql/test/library-tests/Constants/Constants.ql b/javascript/ql/test/library-tests/Constants/Constants.ql
index dcd49275a86..903fe90bc91 100644
--- a/javascript/ql/test/library-tests/Constants/Constants.ql
+++ b/javascript/ql/test/library-tests/Constants/Constants.ql
@@ -2,3 +2,5 @@ import javascript
 
 from ConstantExpr c
 select c
+
+query int getIntValue(Expr e) { result = e.getIntValue() }
diff --git a/javascript/ql/test/library-tests/Constants/tst.js b/javascript/ql/test/library-tests/Constants/tst.js
index 0a24e13abc1..9e6e80ffaeb 100644
--- a/javascript/ql/test/library-tests/Constants/tst.js
+++ b/javascript/ql/test/library-tests/Constants/tst.js
@@ -48,3 +48,6 @@ x = 1;
 x.p = 1;
 x += 1;
 x += x;
+
+x = 1_000;
+x = 1_000_123;