diff --git a/Source/DafnyCore/AST/Expressions/NestedMatchExpr.cs b/Source/DafnyCore/AST/Expressions/NestedMatchExpr.cs
index a095c553cdf..5631075e21d 100644
--- a/Source/DafnyCore/AST/Expressions/NestedMatchExpr.cs
+++ b/Source/DafnyCore/AST/Expressions/NestedMatchExpr.cs
@@ -67,12 +67,6 @@ public void Resolve(Resolver resolver, ResolutionContext resolutionContext) {
       return;
     }
 
-    var dtd = sourceType.AsDatatype;
-    var subst = new Dictionary<TypeParameter, Type>();
-    if (dtd != null) {
-      subst = TypeParameter.SubstitutionMap(dtd.TypeArgs, sourceType.TypeArgs);
-    }
-
     Type = new InferredTypeProxy();
     foreach (var kase in Cases) {
       resolver.scope.PushMarker();
diff --git a/Test/git-issues/git-issue-3333.dfy b/Test/git-issues/git-issue-3333.dfy
new file mode 100644
index 00000000000..2a8f1d345fc
--- /dev/null
+++ b/Test/git-issues/git-issue-3333.dfy
@@ -0,0 +1,13 @@
+// RUN: %exits-with 2 %baredafny verify %args "%s" > "%t"
+// RUN: %diff "%s.expect" "%t"
+
+newtype uint16 = x: int | 0 <= x < 0x1_0000
+
+datatype Datatype = A | B
+{
+  function method Foo(): uint16 {
+    match this
+    case A => 1
+    case B => 2
+  }
+}
diff --git a/Test/git-issues/git-issue-3333.dfy.expect b/Test/git-issues/git-issue-3333.dfy.expect
new file mode 100644
index 00000000000..a3b0d948c38
--- /dev/null
+++ b/Test/git-issues/git-issue-3333.dfy.expect
@@ -0,0 +1,2 @@
+git-issue-3333.dfy(8,18): Error: Function body type mismatch (expected uint16, got int)
+1 resolution/type errors detected in git-issue-3333.dfy
diff --git a/docs/dev/news/3333.fix b/docs/dev/news/3333.fix
new file mode 100644
index 00000000000..c8e9bcf2df0
--- /dev/null
+++ b/docs/dev/news/3333.fix
@@ -0,0 +1 @@
+Match expressions no longer incorrectly convert between newtypes and their basetype