diff --git a/src/resolver/function_validation_test.cc b/src/resolver/function_validation_test.cc
index 5f38b877ea..386c9dfdc8 100644
--- a/src/resolver/function_validation_test.cc
+++ b/src/resolver/function_validation_test.cc
@@ -461,8 +461,8 @@ TEST_F(ResolverFunctionValidationTest, WorkgroupSize_MismatchTypeU32) {
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "12:34 error: workgroup_size parameters must be of the same "
-            "type, either i32 or u32");
+            "12:34 error: workgroup_size arguments must be of the same type, "
+            "either i32 or u32");
 }
 
 TEST_F(ResolverFunctionValidationTest, WorkgroupSize_MismatchTypeI32) {
@@ -475,8 +475,8 @@ TEST_F(ResolverFunctionValidationTest, WorkgroupSize_MismatchTypeI32) {
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "12:34 error: workgroup_size parameters must be of the same "
-            "type, either i32 or u32");
+            "12:34 error: workgroup_size arguments must be of the same type, "
+            "either i32 or u32");
 }
 
 TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Const_TypeMismatch) {
@@ -490,8 +490,8 @@ TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Const_TypeMismatch) {
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "12:34 error: workgroup_size parameters must be of the same "
-            "type, either i32 or u32");
+            "12:34 error: workgroup_size arguments must be of the same type, "
+            "either i32 or u32");
 }
 
 TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Const_TypeMismatch2) {
@@ -507,8 +507,8 @@ TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Const_TypeMismatch2) {
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "12:34 error: workgroup_size parameters must be of the same "
-            "type, either i32 or u32");
+            "12:34 error: workgroup_size arguments must be of the same type, "
+            "either i32 or u32");
 }
 TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Mismatch_ConstU32) {
   // let x = 4u;
@@ -524,8 +524,8 @@ TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Mismatch_ConstU32) {
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "12:34 error: workgroup_size parameters must be of the same "
-            "type, either i32 or u32");
+            "12:34 error: workgroup_size arguments must be of the same type, "
+            "either i32 or u32");
 }
 
 TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Literal_BadType) {
@@ -539,7 +539,7 @@ TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Literal_BadType) {
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "12:34 error: workgroup_size parameter must be either literal or "
+            "12:34 error: workgroup_size argument must be either literal or "
             "module-scope constant of type i32 or u32");
 }
 
@@ -554,7 +554,7 @@ TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Literal_Negative) {
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "12:34 error: workgroup_size parameter must be at least 1");
+            "12:34 error: workgroup_size argument must be at least 1");
 }
 
 TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Literal_Zero) {
@@ -568,7 +568,7 @@ TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Literal_Zero) {
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "12:34 error: workgroup_size parameter must be at least 1");
+            "12:34 error: workgroup_size argument must be at least 1");
 }
 
 TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Const_BadType) {
@@ -582,7 +582,7 @@ TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Const_BadType) {
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "12:34 error: workgroup_size parameter must be either literal or "
+            "12:34 error: workgroup_size argument must be either literal or "
             "module-scope constant of type i32 or u32");
 }
 
@@ -597,7 +597,7 @@ TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Const_Negative) {
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "12:34 error: workgroup_size parameter must be at least 1");
+            "12:34 error: workgroup_size argument must be at least 1");
 }
 
 TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Const_Zero) {
@@ -611,7 +611,7 @@ TEST_F(ResolverFunctionValidationTest, WorkgroupSize_Const_Zero) {
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "12:34 error: workgroup_size parameter must be at least 1");
+            "12:34 error: workgroup_size argument must be at least 1");
 }
 
 TEST_F(ResolverFunctionValidationTest,
@@ -627,7 +627,7 @@ TEST_F(ResolverFunctionValidationTest,
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "12:34 error: workgroup_size parameter must be at least 1");
+            "12:34 error: workgroup_size argument must be at least 1");
 }
 
 TEST_F(ResolverFunctionValidationTest, WorkgroupSize_NonConst) {
@@ -641,10 +641,24 @@ TEST_F(ResolverFunctionValidationTest, WorkgroupSize_NonConst) {
 
   EXPECT_FALSE(r()->Resolve());
   EXPECT_EQ(r()->error(),
-            "12:34 error: workgroup_size parameter must be either literal or "
+            "12:34 error: workgroup_size argument must be either literal or "
             "module-scope constant of type i32 or u32");
 }
 
+TEST_F(ResolverFunctionValidationTest, WorkgroupSize_InvalidExpr) {
+  // [[stage(compute), workgroup_size(i32(1))]
+  // fn main() {}
+  Func("main", {}, ty.void_(), {},
+       {Stage(ast::PipelineStage::kCompute),
+        WorkgroupSize(
+            Construct(Source{Source::Location{12, 34}}, ty.i32(), 1))});
+
+  EXPECT_FALSE(r()->Resolve());
+  EXPECT_EQ(r()->error(),
+            "12:34 error: workgroup_size argument must be either a literal or "
+            "a module-scope constant");
+}
+
 TEST_F(ResolverFunctionValidationTest, ReturnIsConstructible_NonPlain) {
   auto* ret_type =
       ty.pointer(Source{{12, 34}}, ty.i32(), ast::StorageClass::kFunction);
diff --git a/src/resolver/resolver.cc b/src/resolver/resolver.cc
index 1c9e86705b..9c3058d6ac 100644
--- a/src/resolver/resolver.cc
+++ b/src/resolver/resolver.cc
@@ -1866,10 +1866,10 @@ bool Resolver::Function(ast::Function* func) {
       }
 
       constexpr const char* kErrBadType =
-          "workgroup_size parameter must be either literal or module-scope "
+          "workgroup_size argument must be either literal or module-scope "
           "constant of type i32 or u32";
       constexpr const char* kErrInconsistentType =
-          "workgroup_size parameters must be of the same type, either i32 "
+          "workgroup_size arguments must be of the same type, either i32 "
           "or u32";
 
       auto* ty = TypeOf(expr);
@@ -1908,6 +1908,12 @@ bool Resolver::Function(ast::Function* func) {
           info->workgroup_size[i].value = 0;
           continue;
         }
+      } else if (!expr->Is<ast::ScalarConstructorExpression>()) {
+        AddError(
+            "workgroup_size argument must be either a literal or a "
+            "module-scope constant",
+            values[i]->source());
+        return false;
       }
 
       auto val = ConstantValueOf(expr);
@@ -1918,7 +1924,7 @@ bool Resolver::Function(ast::Function* func) {
       }
       // Validate and set the default value for this dimension.
       if (is_i32 ? val.Elements()[0].i32 < 1 : val.Elements()[0].u32 < 1) {
-        AddError("workgroup_size parameter must be at least 1",
+        AddError("workgroup_size argument must be at least 1",
                  values[i]->source());
         return false;
       }