diff --git a/src/coreclr/interpreter/compiler.cpp b/src/coreclr/interpreter/compiler.cpp
index 924953f8419da6..6a9ce4b73f987d 100644
--- a/src/coreclr/interpreter/compiler.cpp
+++ b/src/coreclr/interpreter/compiler.cpp
@@ -3938,6 +3938,18 @@ void InterpCompiler::GenerateCode(CORINFO_METHOD_INFO* methodInfo)
                 break;
             }
 
+            case CEE_CPOBJ:
+            {
+                CHECK_STACK(2);
+                CORINFO_RESOLVED_TOKEN resolvedToken;
+                ResolveToken(getU4LittleEndian(m_ip + 1), CORINFO_TOKENKIND_Class, &resolvedToken);
+                InterpType interpType = GetInterpType(m_compHnd->asCorInfoType(resolvedToken.hClass));
+                EmitLdind(interpType, resolvedToken.hClass, 0);
+                EmitStind(interpType, resolvedToken.hClass, 0, false);
+                m_ip += 5;
+                break;
+            }
+
             case CEE_RET:
             {
                 CORINFO_SIG_INFO sig = methodInfo->args;
@@ -5500,7 +5512,9 @@ void InterpCompiler::GenerateCode(CORINFO_METHOD_INFO* methodInfo)
                         // Length is natural unsigned int
                         if (m_pStackPointer[-1].type == StackTypeI4)
                         {
-                            EmitConv(m_pStackPointer - 1, StackTypeI8, INTOP_MOV_8);
+                            // The localloc instruction allocates size (type native unsigned int or U4) bytes from the local dynamic memory pool ...
+                            // So the size is currently U4 and needs to be promoted to U8
+                            EmitConv(m_pStackPointer - 1, StackTypeI8, INTOP_CONV_U8_U4);
                             m_pStackPointer[-1].type = StackTypeI8;
                         }
 #endif
@@ -5615,6 +5629,21 @@ void InterpCompiler::GenerateCode(CORINFO_METHOD_INFO* methodInfo)
                         m_ip += 5;
                         break;
                     }
+                    case CEE_INITBLK:
+                    {
+                        if (volatile_)
+                        {
+                            AddIns(INTOP_MEMBAR);
+                            volatile_ = false;
+                        }
+
+                        CHECK_STACK(3);
+                        AddIns(INTOP_INITBLK);
+                        m_pStackPointer -= 3;
+                        m_pLastNewIns->SetSVars3(m_pStackPointer[0].var, m_pStackPointer[1].var, m_pStackPointer[2].var);
+                        m_ip++;
+                        break;
+                    }
                     case CEE_CPBLK:
                         CHECK_STACK(3);
                         if (volatile_)
diff --git a/src/coreclr/interpreter/intops.def b/src/coreclr/interpreter/intops.def
index 5850997ec29cc9..23de4306bbbdc4 100644
--- a/src/coreclr/interpreter/intops.def
+++ b/src/coreclr/interpreter/intops.def
@@ -397,6 +397,7 @@ OPDEF(INTOP_GENERICLOOKUP, "generic", 4, 1, 1, InterpOpGenericLookup)
 OPDEF(INTOP_CALL_FINALLY, "call.finally", 2, 0, 0, InterpOpBranch)
 
 OPDEF(INTOP_ZEROBLK_IMM, "zeroblk.imm", 3, 0, 1, InterpOpInt)
+OPDEF(INTOP_INITBLK, "initblk", 4, 0, 3, InterpOpNoArgs)
 OPDEF(INTOP_CPBLK, "cpblk", 4, 0, 3, InterpOpNoArgs)
 OPDEF(INTOP_LOCALLOC, "localloc", 3, 1, 1, InterpOpNoArgs)
 OPDEF(INTOP_BREAKPOINT, "breakpoint", 1, 0, 0, InterpOpNoArgs)
diff --git a/src/coreclr/vm/interpexec.cpp b/src/coreclr/vm/interpexec.cpp
index 5c82f07e4ec820..d452448dd22dc7 100644
--- a/src/coreclr/vm/interpexec.cpp
+++ b/src/coreclr/vm/interpexec.cpp
@@ -2172,6 +2172,18 @@ void InterpExecMethod(InterpreterFrame *pInterpreterFrame, InterpMethodContextFr
                     ip += 4;
                     break;
                 }
+                case INTOP_INITBLK:
+                {
+                    void* dst = LOCAL_VAR(ip[1], void*);
+                    uint8_t value = LOCAL_VAR(ip[2], uint8_t);
+                    uint32_t size = LOCAL_VAR(ip[3], uint32_t);
+                    if (size && !dst)
+                        COMPlusThrow(kNullReferenceException);
+                    else
+                        memset(dst, value, size);
+                    ip += 4;
+                    break;
+                }
                 case INTOP_LOCALLOC:
                 {
                     size_t len = LOCAL_VAR(ip[2], size_t);
diff --git a/src/coreclr/vm/jitinterface.cpp b/src/coreclr/vm/jitinterface.cpp
index da018369afecf0..9dbdd5ac105776 100644
--- a/src/coreclr/vm/jitinterface.cpp
+++ b/src/coreclr/vm/jitinterface.cpp
@@ -1920,15 +1920,15 @@ bool CEEInfo::canAllocateOnStack(CORINFO_CLASS_HANDLE clsHnd)
 unsigned CEEInfo::getClassAlignmentRequirement(CORINFO_CLASS_HANDLE type, bool fDoubleAlignHint)
 {
     CONTRACTL {
-        NOTHROW;
-        GC_NOTRIGGER;
+        THROWS;
+        GC_TRIGGERS;
         MODE_PREEMPTIVE;
     } CONTRACTL_END;
 
     // Default alignment is sizeof(void*)
     unsigned result = TARGET_POINTER_SIZE;
 
-    JIT_TO_EE_TRANSITION_LEAF();
+    JIT_TO_EE_TRANSITION();
 
     TypeHandle clsHnd(type);
 
@@ -1950,14 +1950,14 @@ unsigned CEEInfo::getClassAlignmentRequirement(CORINFO_CLASS_HANDLE type, bool f
         result = getClassAlignmentRequirementStatic(clsHnd);
     }
 
-    EE_TO_JIT_TRANSITION_LEAF();
+    EE_TO_JIT_TRANSITION();
 
     return result;
 }
 
 unsigned CEEInfo::getClassAlignmentRequirementStatic(TypeHandle clsHnd)
 {
-    LIMITED_METHOD_CONTRACT;
+    STANDARD_VM_CONTRACT;
 
     // Default alignment is sizeof(void*)
     unsigned result = TARGET_POINTER_SIZE;