diff --git a/include/clang/AST/Decl.h b/include/clang/AST/Decl.h
index 1b1b1df..3e1f4ba 100644
--- a/include/clang/AST/Decl.h
+++ b/include/clang/AST/Decl.h
@@ -1280,7 +1280,7 @@
   /// Whether this virtual function is pure, i.e. makes the containing class
   /// abstract.
   bool isPure() const { return IsPure; }
-  void setPure(bool P = true) { IsPure = P; }
+  void setPure(bool P = true);
 
   /// Whether this function is "trivial" in some specialized C++ senses.
   /// Can only be true for default constructors, copy constructors,
diff --git a/include/clang/AST/DeclCXX.h b/include/clang/AST/DeclCXX.h
index 786393c..cdc6d8c 100644
--- a/include/clang/AST/DeclCXX.h
+++ b/include/clang/AST/DeclCXX.h
@@ -412,6 +412,9 @@
   /// members have been added. It will be invoked by DeclContext::addDecl()
   /// whenever a member is added to this record.
   void addedMember(Decl *D);
+
+  void markedVirtualFunctionPure();
+  friend void FunctionDecl::setPure(bool);
   
 protected:
   CXXRecordDecl(Kind K, TagKind TK, DeclContext *DC,
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 2f3c006..081e5ee 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -966,6 +966,13 @@
     EndRangeLoc = B->getLocEnd();
 }
 
+void FunctionDecl::setPure(bool P) {
+  IsPure = P;
+  if (P)
+    if (CXXRecordDecl *Parent = dyn_cast<CXXRecordDecl>(getDeclContext()))
+      Parent->markedVirtualFunctionPure();
+}
+
 bool FunctionDecl::isMain() const {
   ASTContext &Context = getASTContext();
   return !Context.getLangOptions().Freestanding &&
diff --git a/lib/AST/DeclCXX.cpp b/lib/AST/DeclCXX.cpp
index 7cdffb7..036292b 100644
--- a/lib/AST/DeclCXX.cpp
+++ b/lib/AST/DeclCXX.cpp
@@ -319,8 +319,13 @@
   return GetBestOverloadCandidateSimple(Found);
 }
 
-void
-CXXRecordDecl::addedMember(Decl *D) {
+void CXXRecordDecl::markedVirtualFunctionPure() {
+  // C++ [class.abstract]p2: 
+  //   A class is abstract if it has at least one pure virtual function.
+  data().Abstract = true;
+}
+
+void CXXRecordDecl::addedMember(Decl *D) {
   // Ignore friends and invalid declarations.
   if (D->getFriendObjectKind() || D->isInvalidDecl())
     return;
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 63acb09..425389a 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -6668,9 +6668,6 @@
 bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) {
   if (Method->isVirtual() || Method->getParent()->isDependentContext()) {
     Method->setPure();
-    
-    // A class is abstract if at least one function is pure virtual.
-    Method->getParent()->setAbstract(true);
     return false;
   }