diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 9d733ca032bb..22a2ef7454b2 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -5295,11 +5295,18 @@ public:
                             ArrayRef<CXXCtorInitializer*> MemInits,
                             bool AnyErrors);
 
+  /// \brief Check class-level dllimport/dllexport attribute. The caller must
+  /// ensure that referenceDLLExportedClassMethods is called some point later
+  /// when all outer classes of Class are complete.
   void checkClassLevelDLLAttribute(CXXRecordDecl *Class);
+
+  void referenceDLLExportedClassMethods();
+
   void propagateDLLAttrToBaseClassTemplate(
       CXXRecordDecl *Class, Attr *ClassAttr,
       ClassTemplateSpecializationDecl *BaseTemplateSpec,
       SourceLocation BaseLoc);
+
   void CheckCompletedCXXClass(CXXRecordDecl *Record);
   void ActOnFinishCXXMemberSpecification(Scope* S, SourceLocation RLoc,
                                          Decl *TagDecl,
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index c160f444ca53..389012034166 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -9533,6 +9533,10 @@ void Sema::ActOnFinishCXXNonNestedClass(Decl *D) {
   if (RD && Context.getTargetInfo().getCXXABI().isMicrosoft())
     getDefaultArgExprsForConstructors(*this, RD);
 
+  referenceDLLExportedClassMethods();
+}
+
+void Sema::referenceDLLExportedClassMethods() {
   if (!DelayedDllExportClasses.empty()) {
     // Calling ReferenceDllExportedMethods might cause the current function to
     // be called again, so use a local copy of DelayedDllExportClasses.
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 38df76ee3153..3b85b98abdd3 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -7458,7 +7458,13 @@ Sema::ActOnExplicitInstantiation(Scope *S,
             getDLLAttr(Specialization)->clone(getASTContext()));
         A->setInherited(true);
         Def->addAttr(A);
+
+        // We reject explicit instantiations in class scope, so there should
+        // never be any delayed exported classes to worry about.
+        assert(DelayedDllExportClasses.empty() &&
+               "delayed exports present at explicit instantiation");
         checkClassLevelDLLAttribute(Def);
+        referenceDLLExportedClassMethods();
 
         // Propagate attribute to base class templates.
         for (auto &B : Def->bases()) {
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index 56858bcc7e6a..db3f47fd9167 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -1949,6 +1949,13 @@ Sema::InstantiateClass(SourceLocation PointOfInstantiation,
   bool MergeWithParentScope = !Instantiation->isDefinedOutsideFunctionOrMethod();
   LocalInstantiationScope Scope(*this, MergeWithParentScope);
 
+  // All dllexported classes created during instantiation should be fully
+  // emitted after instantiation completes. We may not be ready to emit any
+  // delayed classes already on the stack, so save them away and put them back
+  // later.
+  decltype(DelayedDllExportClasses) ExportedClasses;
+  std::swap(ExportedClasses, DelayedDllExportClasses);
+
   // Pull attributes from the pattern onto the instantiation.
   InstantiateAttrs(TemplateArgs, Pattern, Instantiation);
 
@@ -2034,6 +2041,9 @@ Sema::InstantiateClass(SourceLocation PointOfInstantiation,
   // default arg exprs for default constructors if necessary now.
   ActOnFinishCXXNonNestedClass(Instantiation);
 
+  // Put back the delayed exported classes that we moved out of the way.
+  std::swap(ExportedClasses, DelayedDllExportClasses);
+
   // Instantiate late parsed attributes, and attach them to their decls.
   // See Sema::InstantiateAttrs
   for (LateInstantiatedAttrVec::iterator I = LateAttrs.begin(),
diff --git a/clang/test/CodeGenCXX/dllexport-pr26549.cpp b/clang/test/CodeGenCXX/dllexport-pr26549.cpp
new file mode 100644
index 000000000000..ceb2e0685ef1
--- /dev/null
+++ b/clang/test/CodeGenCXX/dllexport-pr26549.cpp
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 %s -fms-extensions -triple x86_64-windows-msvc -emit-llvm -o - | FileCheck %s
+
+template <typename> struct MessageT { };
+extern template struct MessageT<int>;
+
+// CHECK: define weak_odr dllexport {{.*}} %struct.MessageT* @"\01??4?$MessageT@H@@QEAAAEAU0@AEBU0@@Z"(
+template struct __declspec(dllexport) MessageT<int>;
+// Previously we crashed when this dllexport was the last thing in the file.
+// DO NOT ADD MORE TESTS AFTER THIS LINE!
diff --git a/clang/test/CodeGenCXX/dllexport.cpp b/clang/test/CodeGenCXX/dllexport.cpp
index 1412ad866bd3..04007e8212dd 100644
--- a/clang/test/CodeGenCXX/dllexport.cpp
+++ b/clang/test/CodeGenCXX/dllexport.cpp
@@ -777,6 +777,17 @@ struct __declspec(dllexport) Baz {
 // M32-DAG: define weak_odr dllexport x86_thiscallcc dereferenceable(1) %"struct.InClassInits::Baz"* @"\01??4Baz@InClassInits@@QAEAAU01@ABU01@@Z"
 }
 
+// We had an issue where instantiating A would force emission of B's delayed
+// exported methods.
+namespace pr26490 {
+template <typename T> struct A { };
+struct __declspec(dllexport) B {
+  B(int = 0) {}
+  A<int> m_fn1() {}
+};
+// M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01??_FB@pr26490@@QAEXXZ"
+}
+
 
 //===----------------------------------------------------------------------===//
 // Classes with template base classes