diff --git a/src/ast/module.cc b/src/ast/module.cc
index e5c5015d71..dfca88a479 100644
--- a/src/ast/module.cc
+++ b/src/ast/module.cc
@@ -29,8 +29,29 @@ const Import* Module::FindImportByName(const std::string& name) {
 
 bool Module::IsValid() const {
   for (const auto& import : imports_) {
-    if (!import->IsValid())
+    if (import == nullptr || !import->IsValid()) {
       return false;
+    }
+  }
+  for (const auto& var : global_variables_) {
+    if (var == nullptr || !var->IsValid()) {
+      return false;
+    }
+  }
+  for (const auto& ep : entry_points_) {
+    if (ep == nullptr || !ep->IsValid()) {
+      return false;
+    }
+  }
+  for (const auto& alias : alias_types_) {
+    if (alias == nullptr) {
+      return false;
+    }
+  }
+  for (const auto& func : functions_) {
+    if (func == nullptr || !func->IsValid()) {
+      return false;
+    }
   }
   return true;
 }
diff --git a/src/ast/module_test.cc b/src/ast/module_test.cc
index 2cf16267b0..64fd31b2f7 100644
--- a/src/ast/module_test.cc
+++ b/src/ast/module_test.cc
@@ -17,6 +17,11 @@
 #include <utility>
 
 #include "gtest/gtest.h"
+#include "src/ast/entry_point.h"
+#include "src/ast/function.h"
+#include "src/ast/import.h"
+#include "src/ast/type/f32_type.h"
+#include "src/ast/variable.h"
 
 namespace tint {
 namespace ast {
@@ -62,17 +67,104 @@ TEST_F(ModuleTest, IsValid_Empty) {
   EXPECT_TRUE(m.IsValid());
 }
 
-TEST_F(ModuleTest, IsValid_InvalidImport) {
-  Module m;
-  m.AddImport(std::make_unique<Import>());
-  EXPECT_FALSE(m.IsValid());
-}
-
-TEST_F(ModuleTest, IsValid_ValidImport) {
+TEST_F(ModuleTest, IsValid_Import) {
   Module m;
   m.AddImport(std::make_unique<Import>("GLSL.std.430", "std::glsl"));
   EXPECT_TRUE(m.IsValid());
 }
 
+TEST_F(ModuleTest, IsValid_Null_Import) {
+  Module m;
+  m.AddImport(nullptr);
+  EXPECT_FALSE(m.IsValid());
+}
+
+TEST_F(ModuleTest, IsValid_Invalid_Import) {
+  Module m;
+  m.AddImport(std::make_unique<Import>());
+  EXPECT_FALSE(m.IsValid());
+}
+
+TEST_F(ModuleTest, IsValid_GlobalVariable) {
+  type::F32Type f32;
+  auto var = std::make_unique<Variable>("var", StorageClass::kInput, &f32);
+
+  Module m;
+  m.AddGlobalVariable(std::move(var));
+  EXPECT_TRUE(m.IsValid());
+}
+
+TEST_F(ModuleTest, IsValid_Null_GlobalVariable) {
+  Module m;
+  m.AddGlobalVariable(nullptr);
+  EXPECT_FALSE(m.IsValid());
+}
+
+TEST_F(ModuleTest, IsValid_Invalid_GlobalVariable) {
+  auto var = std::make_unique<Variable>("var", StorageClass::kInput, nullptr);
+
+  Module m;
+  m.AddGlobalVariable(std::move(var));
+  EXPECT_FALSE(m.IsValid());
+}
+
+TEST_F(ModuleTest, IsValid_EntryPoint) {
+  Module m;
+  m.AddEntryPoint(
+      std::make_unique<EntryPoint>(PipelineStage::kVertex, "main", "vtx_main"));
+  EXPECT_TRUE(m.IsValid());
+}
+
+TEST_F(ModuleTest, IsValid_Null_EntryPoint) {
+  Module m;
+  m.AddEntryPoint(nullptr);
+  EXPECT_FALSE(m.IsValid());
+}
+
+TEST_F(ModuleTest, IsValid_Invalid_EntryPoint) {
+  Module m;
+  m.AddEntryPoint(std::make_unique<EntryPoint>());
+  EXPECT_FALSE(m.IsValid());
+}
+
+TEST_F(ModuleTest, IsValid_Alias) {
+  type::F32Type f32;
+  type::AliasType alias("alias", &f32);
+
+  Module m;
+  m.AddAliasType(&alias);
+  EXPECT_TRUE(m.IsValid());
+}
+
+TEST_F(ModuleTest, IsValid_Null_Alias) {
+  Module m;
+  m.AddAliasType(nullptr);
+  EXPECT_FALSE(m.IsValid());
+}
+
+TEST_F(ModuleTest, IsValid_Function) {
+  type::F32Type f32;
+  auto func = std::make_unique<Function>(
+      "main", std::vector<std::unique_ptr<Variable>>(), &f32);
+
+  Module m;
+  m.AddFunction(std::move(func));
+  EXPECT_TRUE(m.IsValid());
+}
+
+TEST_F(ModuleTest, IsValid_Null_Function) {
+  Module m;
+  m.AddFunction(nullptr);
+  EXPECT_FALSE(m.IsValid());
+}
+
+TEST_F(ModuleTest, IsValid_Invalid_Function) {
+  auto func = std::make_unique<Function>();
+
+  Module m;
+  m.AddFunction(std::move(func));
+  EXPECT_FALSE(m.IsValid());
+}
+
 }  // namespace ast
 }  // namespace tint