diff --git a/runtime/debugger.cc b/runtime/debugger.cc
index 984f287..07cb9d1 100644
--- a/runtime/debugger.cc
+++ b/runtime/debugger.cc
@@ -1131,13 +1131,14 @@
 JDWP::JdwpError Dbg::GetSourceFile(JDWP::RefTypeId class_id, std::string& result) {
   JDWP::JdwpError status;
   mirror::Class* c = DecodeClass(class_id, status);
-  if (c == NULL) {
+  if (c == nullptr) {
     return status;
   }
-  if (c->IsProxyClass()) {
+  const char* source_file = c->GetSourceFile();
+  if (source_file == nullptr) {
     return JDWP::ERR_ABSENT_INFORMATION;
   }
-  result = c->GetSourceFile();
+  result = source_file;
   return JDWP::ERR_NONE;
 }
 
diff --git a/runtime/mirror/class.cc b/runtime/mirror/class.cc
index 4869b45..c3aac5e 100644
--- a/runtime/mirror/class.cc
+++ b/runtime/mirror/class.cc
@@ -771,7 +771,10 @@
   std::string descriptor(GetDescriptor());
   const DexFile& dex_file = GetDexFile();
   const DexFile::ClassDef* dex_class_def = GetClassDef();
-  CHECK(dex_class_def != nullptr) << "No class def for class " << PrettyClass(this);
+  if (dex_class_def == nullptr) {
+    // Generated classes have no class def.
+    return nullptr;
+  }
   return dex_file.GetSourceFile(*dex_class_def);
 }
 
diff --git a/runtime/proxy_test.cc b/runtime/proxy_test.cc
index f38fb21..9724bcc 100644
--- a/runtime/proxy_test.cc
+++ b/runtime/proxy_test.cc
@@ -128,12 +128,12 @@
   ASSERT_TRUE(proxy_class->IsProxyClass());
   ASSERT_TRUE(proxy_class->IsInitialized());
 
-  // Check ClassHelper for proxy.
-  EXPECT_EQ(proxy_class->NumDirectInterfaces(), 2U);  // Interfaces$I and Interfaces$J.
+  EXPECT_EQ(2U, proxy_class->NumDirectInterfaces());  // Interfaces$I and Interfaces$J.
   EXPECT_EQ(I.Get(), mirror::Class::GetDirectInterface(soa.Self(), proxy_class, 0));
   EXPECT_EQ(J.Get(), mirror::Class::GetDirectInterface(soa.Self(), proxy_class, 1));
   std::string proxy_class_descriptor(proxy_class->GetDescriptor());
   EXPECT_STREQ("L$Proxy1234;", proxy_class_descriptor.c_str());
+  EXPECT_EQ(nullptr, proxy_class->GetSourceFile());
 }
 
 // Creates a proxy class and check FieldHelper works correctly.