diff --git a/ddmd/root/rmem.d b/ddmd/root/rmem.d
index 450d45e826..fd966b72b1 100644
--- a/ddmd/root/rmem.d
+++ b/ddmd/root/rmem.d
@@ -192,6 +192,14 @@ else
             return cast(Object)p;
         }
 
+      version (LDC)
+      {
+        extern (C) Object _d_allocclass(const ClassInfo ci) nothrow
+        {
+            return cast(Object)allocmemory(ci.init.length);
+        }
+      }
+
         extern (C) void* _d_newitemT(TypeInfo ti) nothrow
         {
             auto p = allocmemory(ti.tsize);
diff --git a/gen/classes.cpp b/gen/classes.cpp
index 35f1293d90..4ae4382255 100644
--- a/gen/classes.cpp
+++ b/gen/classes.cpp
@@ -84,8 +84,8 @@ DValue *DtoNewClass(Loc &loc, TypeClass *tc, NewExp *newexp) {
   // allocate
   LLValue *mem;
   if (newexp->onstack) {
-    // FIXME align scope class to its largest member
-    mem = DtoRawAlloca(DtoType(tc)->getContainedType(0), 0, ".newclass_alloca");
+    mem = DtoRawAlloca(DtoType(tc)->getContainedType(0), DtoAlignment(tc),
+                       ".newclass_alloca");
   }
   // custom allocator
   else if (newexp->allocator) {
@@ -97,7 +97,7 @@ DValue *DtoNewClass(Loc &loc, TypeClass *tc, NewExp *newexp) {
   // default allocator
   else {
     llvm::Function *fn =
-        getRuntimeFunction(loc, gIR->module, "_d_newclass");
+        getRuntimeFunction(loc, gIR->module, "_d_allocclass");
     LLConstant *ci = DtoBitCast(getIrAggr(tc->sym)->getClassInfoSymbol(),
                                 DtoType(Type::typeinfoclass->type));
     mem =
diff --git a/gen/passes/GarbageCollect2Stack.cpp b/gen/passes/GarbageCollect2Stack.cpp
index 346f0b5044..5483e5b528 100644
--- a/gen/passes/GarbageCollect2Stack.cpp
+++ b/gen/passes/GarbageCollect2Stack.cpp
@@ -255,7 +255,7 @@ public:
   }
 };
 
-// FunctionInfo for _d_newclass
+// FunctionInfo for _d_allocclass
 class AllocClassFI : public FunctionInfo {
 public:
   bool analyze(CallSite CS, const Analysis &A) override {
@@ -436,7 +436,7 @@ GarbageCollect2Stack::GarbageCollect2Stack()
   KnownFunctions["_d_allocmemoryT"] = &AllocMemoryT;
   KnownFunctions["_d_newarrayU"] = &NewArrayU;
   KnownFunctions["_d_newarrayT"] = &NewArrayT;
-  KnownFunctions["_d_newclass"] = &AllocClass;
+  KnownFunctions["_d_allocclass"] = &AllocClass;
   KnownFunctions["_d_allocmemory"] = &AllocMemory;
 }
 
diff --git a/gen/passes/SimplifyDRuntimeCalls.cpp b/gen/passes/SimplifyDRuntimeCalls.cpp
index ef5b98abd5..f056b1410c 100644
--- a/gen/passes/SimplifyDRuntimeCalls.cpp
+++ b/gen/passes/SimplifyDRuntimeCalls.cpp
@@ -372,6 +372,7 @@ void SimplifyDRuntimeCalls::InitOptimizations() {
   Optimizations["_d_newarraymiT"] = &Allocation;
   Optimizations["_d_newarraymvT"] = &Allocation;
   Optimizations["_d_newclass"] = &Allocation;
+  Optimizations["_d_allocclass"] = &Allocation;
 }
 
 /// runOnFunction - Top level algorithm.
diff --git a/gen/runtime.cpp b/gen/runtime.cpp
index 5e25494578..1d03f57a42 100644
--- a/gen/runtime.cpp
+++ b/gen/runtime.cpp
@@ -85,6 +85,7 @@ static void checkForImplicitGCCall(const Loc &loc, const char *name) {
         "_d_newarraymiTX",
         "_d_newarrayU",
         "_d_newclass",
+        "_d_allocclass",
         "_d_newitemT",
         "_d_newitemiT",
     };
@@ -397,6 +398,10 @@ static void buildRuntimeModule() {
   createFwdDecl(LINKc, objectTy, {"_d_newclass"}, {classInfoTy}, {STCconst},
                 Attr_NoAlias);
 
+  // Object _d_allocclass(const ClassInfo ci)
+  createFwdDecl(LINKc, objectTy, {"_d_allocclass"}, {classInfoTy}, {STCconst},
+                Attr_NoAlias);
+
   // void* _d_newitemT (TypeInfo ti)
   // void* _d_newitemiT(TypeInfo ti)
   createFwdDecl(LINKc, voidPtrTy, {"_d_newitemT", "_d_newitemiT"}, {typeInfoTy},
diff --git a/runtime/druntime b/runtime/druntime
index 5c5dd37e43..0aeb4da53e 160000
--- a/runtime/druntime
+++ b/runtime/druntime
@@ -1 +1 @@
-Subproject commit 5c5dd37e433afdb5b1f2cd33f170014cdd96312a
+Subproject commit 0aeb4da53e922f7d17401dd13f69b8e355f327f9