diff --git a/formats/debug_switch_user.ksy b/formats/debug_switch_user.ksy
new file mode 100644
index 000000000..563e74b7e
--- /dev/null
+++ b/formats/debug_switch_user.ksy
@@ -0,0 +1,22 @@
+meta:
+  id: debug_switch_user
+  endian: le
+  ks-debug: true
+seq:
+  - id: code
+    type: u1
+  - id: data
+    type:
+      switch-on: code
+      cases:
+        1: one
+        2: two
+types:
+  one:
+    seq:
+      - id: val
+        type: s2
+  two:
+    seq:
+      - id: val
+        type: u2
diff --git a/spec/ks/debug_switch_user.kst b/spec/ks/debug_switch_user.kst
new file mode 100644
index 000000000..01fec2e89
--- /dev/null
+++ b/spec/ks/debug_switch_user.kst
@@ -0,0 +1,7 @@
+id: debug_switch_user
+data: nav_parent_switch.bin
+asserts:
+  - actual: code
+    expected: 1
+  - actual: data.as<debug_switch_user::one>.val
+    expected: -190