diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index ee71116c58a1..fd9c7cf11329 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -5552,7 +5552,8 @@ void ASTContext::getObjCEncodingForStructureImpl(RecordDecl *RDecl,
       if (base->isEmpty())
         continue;
       uint64_t offs = toBits(layout.getVBaseClassOffset(base));
-      if (FieldOrBaseOffsets.find(offs) == FieldOrBaseOffsets.end())
+      if (offs >= uint64_t(toBits(layout.getNonVirtualSize())) &&
+          FieldOrBaseOffsets.find(offs) == FieldOrBaseOffsets.end())
         FieldOrBaseOffsets.insert(FieldOrBaseOffsets.end(),
                                   std::make_pair(offs, base));
     }
diff --git a/clang/test/CodeGenObjCXX/encode.mm b/clang/test/CodeGenObjCXX/encode.mm
index 589db6c0e04d..075d7909d596 100644
--- a/clang/test/CodeGenObjCXX/encode.mm
+++ b/clang/test/CodeGenObjCXX/encode.mm
@@ -214,3 +214,13 @@ public:
 }
 @end
 // CHECK: internal global [41 x i8] c"{dynamic_class=\22_vptr$dynamic_class\22^^?}\00"
+
+namespace PR17142 {
+  struct A { virtual ~A(); };
+  struct B : virtual A { int y; };
+  struct C { virtual ~C(); int z; };
+  struct D : C, B { int a; };
+  struct E : D {};
+  // CHECK: @_ZN7PR171421xE = constant [14 x i8] c"{E=^^?i^^?ii}\00"
+  extern const char x[] = @encode(E);
+}