diff --git a/test/ASTMerge/Inputs/class1.cpp b/test/ASTMerge/Inputs/class1.cpp
new file mode 100644
index 0000000..e13faf0
--- /dev/null
+++ b/test/ASTMerge/Inputs/class1.cpp
@@ -0,0 +1,8 @@
+struct A {
+  int x;
+};
+
+struct B : A {
+  float y;
+  float foo();
+};
diff --git a/test/ASTMerge/Inputs/class2.cpp b/test/ASTMerge/Inputs/class2.cpp
new file mode 100644
index 0000000..91b84dc
--- /dev/null
+++ b/test/ASTMerge/Inputs/class2.cpp
@@ -0,0 +1,8 @@
+struct A {
+  int x;
+};
+
+struct B : A {
+  int y;
+  int foo();
+};
diff --git a/test/ASTMerge/class.cpp b/test/ASTMerge/class.cpp
new file mode 100644
index 0000000..114687f
--- /dev/null
+++ b/test/ASTMerge/class.cpp
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -emit-pch -o %t.1.ast %S/Inputs/class1.cpp
+// RUN: %clang_cc1 -emit-pch -o %t.2.ast %S/Inputs/class2.cpp
+// RUN: %clang_cc1 -ast-merge %t.1.ast -ast-merge %t.2.ast -fsyntax-only %s 2>&1 | FileCheck %s
+
+// CHECK: class1.cpp:5:8: warning: type 'B' has incompatible definitions in different translation units
+// CHECK: class1.cpp:6:9: note: field 'y' has type 'float' here
+// CHECK: class2.cpp:6:7: note: field 'y' has type 'int' here
+
+// FIXME: we should also complain about mismatched types on the method