diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index a153193a53fea626f20b6c106ec97d4e28ac0eb2..af0cd02ed2f128aabd4bb450519d6d4d8fecafb2 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -1655,7 +1655,8 @@ static bool isDefinedInClangModule(const RecordDecl *RD) {
   if (!RD->isExternallyVisible() && RD->getName().empty())
     return false;
   if (auto *CXXDecl = dyn_cast<CXXRecordDecl>(RD)) {
-    assert(CXXDecl->isCompleteDefinition() && "incomplete record definition");
+    if (!CXXDecl->isCompleteDefinition())
+      return false;
     auto TemplateKind = CXXDecl->getTemplateSpecializationKind();
     if (TemplateKind != TSK_Undeclared) {
       // This is a template, check the origin of the first member.
diff --git a/test/Modules/Inputs/DebugNestedA.h b/test/Modules/Inputs/DebugNestedA.h
new file mode 100644
index 0000000000000000000000000000000000000000..58dc2a7df74926cd98ed8429d1ebaf4c7203f9a5
--- /dev/null
+++ b/test/Modules/Inputs/DebugNestedA.h
@@ -0,0 +1,8 @@
+/* -*- C++ -*- */
+template <typename T> class Base {};
+template <typename T> struct A : public Base<A<T>> {
+  void f();
+};
+
+class F {};
+typedef A<F> AF;
diff --git a/test/Modules/Inputs/DebugNestedB.h b/test/Modules/Inputs/DebugNestedB.h
new file mode 100644
index 0000000000000000000000000000000000000000..7f75d0946e20eb6c338cdc886abbc0124722558b
--- /dev/null
+++ b/test/Modules/Inputs/DebugNestedB.h
@@ -0,0 +1,7 @@
+/* -*- C++ -*- */
+#include "DebugNestedA.h"
+class C {
+  void run(AF &af) {
+    af.f();
+  }
+};
diff --git a/test/Modules/Inputs/module.map b/test/Modules/Inputs/module.map
index a683190e18251dcdfdad13804271c79690bc2987..2beb942861a469faf27dadc30a0e16240c689d6d 100644
--- a/test/Modules/Inputs/module.map
+++ b/test/Modules/Inputs/module.map
@@ -422,3 +422,13 @@ module MacroFabs1 {
 module DiagOutOfDate {
   header "DiagOutOfDate.h"
 }
+
+module DebugNestedA {
+  header "DebugNestedA.h"
+  export *
+}
+
+module DebugNestedB {
+  header "DebugNestedB.h"
+  export *
+}