diff --git a/src/AstGen.zig b/src/AstGen.zig
index c4121e0a2003ab6350b58c69cc6aff28d6336262..af0fac04f14bab9786fb5e32b31fa8a1663c8cc7 100644
--- a/src/AstGen.zig
+++ b/src/AstGen.zig
@@ -4724,7 +4724,10 @@ fn containerDecl(
             defer wip_members.deinit();
 
             for (container_decl.ast.members) |member_node| {
-                _ = try containerMember(gz, &namespace.base, &wip_members, member_node);
+                const res = try containerMember(gz, &namespace.base, &wip_members, member_node);
+                if (res == .field) {
+                    return astgen.failNode(member_node, "opaque types cannot have fields", .{});
+                }
             }
 
             try gz.setOpaque(decl_inst, .{
diff --git a/test/cases/compile_errors/opaque_type_with_field.zig b/test/cases/compile_errors/opaque_type_with_field.zig
new file mode 100644
index 0000000000000000000000000000000000000000..6cfa67e5ec480ae460fdc461118833c3f850b417
--- /dev/null
+++ b/test/cases/compile_errors/opaque_type_with_field.zig
@@ -0,0 +1,11 @@
+const Opaque = opaque { foo: i32 };
+export fn entry() void {
+    const foo: ?*Opaque = null;
+    _ = foo;
+}
+
+// error
+// backend=stage2
+// target=native
+//
+// :1:25: error: opaque types cannot have fields
diff --git a/test/cases/compile_errors/stage1/obj/opaque_type_with_field.zig b/test/cases/compile_errors/stage1/obj/opaque_type_with_field.zig
deleted file mode 100644
index 0b87091de945bdf3b94fd987de5496ca4336d839..0000000000000000000000000000000000000000
--- a/test/cases/compile_errors/stage1/obj/opaque_type_with_field.zig
+++ /dev/null
@@ -1,11 +0,0 @@
-const Opaque = opaque { foo: i32 };
-export fn entry() void {
-    const foo: ?*Opaque = null;
-    _ = foo;
-}
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:1:25: error: opaque types cannot have fields