diff --git a/src/resolver/entry_point_validation_test.cc b/src/resolver/entry_point_validation_test.cc
index 6b07e91596..39ddea3ce4 100644
--- a/src/resolver/entry_point_validation_test.cc
+++ b/src/resolver/entry_point_validation_test.cc
@@ -522,24 +522,22 @@ TEST_F(LocationDecorationTests, BadType_Input_Struct_NestedStruct) {
   //   [[location(0)]] b : f32;
   // };
   // struct Input {
-  //   [[location(0)]] a : Inner;
+  //   a : Inner;
   // };
   // [[stage(fragment)]]
   // fn main(param : Input) {}
   auto* inner = Structure(
       "Inner", {Member(Source{{13, 43}}, "a", ty.f32(), {Location(0)})});
-  auto* input = Structure("Input", {Member(Source{{14, 52}}, "a", ty.Of(inner),
-                                           {Location(Source{{12, 34}}, 0)})});
+  auto* input =
+      Structure("Input", {Member(Source{{14, 52}}, "a", ty.Of(inner))});
   auto* param = Param("param", ty.Of(input));
   Func(Source{{12, 34}}, "main", {param}, ty.void_(), {},
        {Stage(ast::PipelineStage::kFragment)});
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "14:52 error: cannot apply 'location' attribute to declaration of "
-            "type 'Inner'\n"
-            "12:34 note: 'location' attribute must only be applied to "
-            "declarations of numeric scalar or numeric vector type");
+            "14:52 error: nested structures cannot be used for entry point IO\n"
+            "12:34 note: while analysing entry point 'main'");
 }
 
 TEST_F(LocationDecorationTests, BadType_Input_Struct_RuntimeArray) {
@@ -666,19 +664,22 @@ TEST_F(LocationDecorationTests, ReturnType_Struct_NestedStruct) {
   //   [[location(0)]] b : f32;
   // };
   // struct Output {
-  //   [[location(0)]] a : Inner;
+  //   a : Inner;
   // };
+  // [[stage(fragment)]]
+  // fn main() -> Output { return Output(); }
   auto* inner = Structure(
       "Inner", {Member(Source{{13, 43}}, "a", ty.f32(), {Location(0)})});
-  Structure("Output", {Member(Source{{14, 52}}, "a", ty.Of(inner),
-                              {Location(Source{{12, 34}}, 0)})});
+  auto* output =
+      Structure("Output", {Member(Source{{14, 52}}, "a", ty.Of(inner))});
+  Func(Source{{12, 34}}, "main", {}, ty.Of(output),
+       {Return(Construct(ty.Of(output)))},
+       {Stage(ast::PipelineStage::kFragment)});
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "14:52 error: cannot apply 'location' attribute to declaration of "
-            "type 'Inner'\n"
-            "12:34 note: 'location' attribute must only be applied to "
-            "declarations of numeric scalar or numeric vector type");
+            "14:52 error: nested structures cannot be used for entry point IO\n"
+            "12:34 note: while analysing entry point 'main'");
 }
 
 TEST_F(LocationDecorationTests, ReturnType_Struct_RuntimeArray) {
diff --git a/src/resolver/resolver.cc b/src/resolver/resolver.cc
index 13231317cc..75b4a82833 100644
--- a/src/resolver/resolver.cc
+++ b/src/resolver/resolver.cc
@@ -1594,6 +1594,12 @@ bool Resolver::ValidateEntryPoint(const ast::Function* func,
 
         if (IsValidationEnabled(
                 decos, ast::DisabledValidation::kEntryPointParameter)) {
+          if (is_struct_member && ty->Is<sem::Struct>()) {
+            AddError("nested structures cannot be used for entry point IO",
+                     source);
+            return false;
+          }
+
           if (!ty->Is<sem::Struct>() && !pipeline_io_attribute) {
             std::string err = "missing entry point IO attribute";
             if (!is_struct_member) {