diff --git a/src/resolver/function_validation_test.cc b/src/resolver/function_validation_test.cc
index da0a2c9fe0..d0c7556f5e 100644
--- a/src/resolver/function_validation_test.cc
+++ b/src/resolver/function_validation_test.cc
@@ -644,6 +644,28 @@ TEST_F(ResolverFunctionValidationTest, ParameterSotreType_AtomicFree) {
   EXPECT_TRUE(r()->Resolve()) << r()->error();
 }
 
+TEST_F(ResolverFunctionValidationTest, ParametersAtLimit) {
+  ast::VariableList params;
+  for (int i = 0; i < 255; i++) {
+    params.emplace_back(Param("param_" + std::to_string(i), ty.i32()));
+  }
+  Func(Source{{12, 34}}, "f", params, ty.void_(), {});
+
+  EXPECT_TRUE(r()->Resolve()) << r()->error();
+}
+
+TEST_F(ResolverFunctionValidationTest, ParametersOverLimit) {
+  ast::VariableList params;
+  for (int i = 0; i < 256; i++) {
+    params.emplace_back(Param("param_" + std::to_string(i), ty.i32()));
+  }
+  Func(Source{{12, 34}}, "f", params, ty.void_(), {});
+
+  EXPECT_FALSE(r()->Resolve());
+  EXPECT_EQ(r()->error(),
+            "12:34 error: functions may declare at most 255 parameters");
+}
+
 struct TestParams {
   ast::StorageClass storage_class;
   bool should_pass;
diff --git a/src/resolver/resolver.cc b/src/resolver/resolver.cc
index dd37815481..8288a3f6b4 100644
--- a/src/resolver/resolver.cc
+++ b/src/resolver/resolver.cc
@@ -1388,6 +1388,11 @@ bool Resolver::ValidateFunction(const ast::Function* func,
     }
   }
 
+  if (func->params().size() > 255) {
+    AddError("functions may declare at most 255 parameters", func->source());
+    return false;
+  }
+
   for (auto* param : func->params()) {
     if (!ValidateFunctionParameter(func, variable_to_info_.at(param))) {
       return false;