diff --git a/test/fixtures/experimental/numeric-literal-separator/identifier-start-0/actual.js b/test/fixtures/experimental/numeric-literal-separator/identifier-start-0/actual.js
new file mode 100644
index 0000000000..adc9bff555
--- /dev/null
+++ b/test/fixtures/experimental/numeric-literal-separator/identifier-start-0/actual.js
@@ -0,0 +1 @@
+_123
diff --git a/test/fixtures/experimental/numeric-literal-separator/identifier-start-0/expected.json b/test/fixtures/experimental/numeric-literal-separator/identifier-start-0/expected.json
new file mode 100644
index 0000000000..70cf57a548
--- /dev/null
+++ b/test/fixtures/experimental/numeric-literal-separator/identifier-start-0/expected.json
@@ -0,0 +1,66 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 4,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 1,
+      "column": 4
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 4,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 1,
+        "column": 4
+      }
+    },
+    "sourceType": "script",
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 4,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 4
+          }
+        },
+        "expression": {
+          "type": "Identifier",
+          "start": 0,
+          "end": 4,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 0
+            },
+            "end": {
+              "line": 1,
+              "column": 4
+            },
+            "identifierName": "_123"
+          },
+          "name": "_123"
+        }
+      }
+    ],
+    "directives": []
+  }
+}
\ No newline at end of file