diff --git a/tests/neg/i4863.scala b/tests/neg/i4863.scala
new file mode 100644
index 000000000000..350554354fe2
--- /dev/null
+++ b/tests/neg/i4863.scala
@@ -0,0 +1,13 @@
+sealed trait Nat
+case class S(n: Nat) extends Nat
+case object Z extends Nat
+
+inline def pred(n: Nat) = inline n match {
+  case S(m) => m
+  case Z =>
+    compiletime.error("n cannot be Z")
+}
+
+class Test {
+  pred(Z) // error
+}
diff --git a/tests/pos/i4863.scala b/tests/pos/i4863.scala
new file mode 100644
index 000000000000..7afec6f00645
--- /dev/null
+++ b/tests/pos/i4863.scala
@@ -0,0 +1,13 @@
+sealed trait Nat
+case class S(n: Nat) extends Nat
+case object Z extends Nat
+
+inline def pred(n: Nat) = inline n match {
+  case S(m) => m
+  case Z =>
+    compiletime.error("n cannot be Z")
+}
+
+class Test {
+  pred(S(Z))
+}