diff --git a/src/mapleall/maple_be/src/be/lower.cpp b/src/mapleall/maple_be/src/be/lower.cpp
index db9ef265a9002138d1914ba4479dfb64258bdbb3..340f1522188e18b29d3a5b79ed0b16027c879db4 100644
--- a/src/mapleall/maple_be/src/be/lower.cpp
+++ b/src/mapleall/maple_be/src/be/lower.cpp
@@ -1186,11 +1186,11 @@ StmtNode *CGLowerer::LowerCall(CallNode &callNode, StmtNode *&nextStmt, BlockNod
     MIRPtrType *pretType = static_cast<MIRPtrType*>((calleeFunc->GetNthParamType(0)));
     CHECK_FATAL(pretType != nullptr, "nullptr is not expected");
     retType = GlobalTables::GetTypeTable().GetTypeFromTyIdx(pretType->GetPointedTyIdx());
-    CHECK_FATAL(retType->GetKind() == kTypeStruct, "make sure retType is a struct type");
+    CHECK_FATAL((retType->GetKind() == kTypeStruct) || (retType->GetKind() == kTypeUnion), "make sure retType is a struct type");
   }
 
   /* if return type is not of a struct, return */
-  if (retType->GetKind() != kTypeStruct) {
+  if ((retType->GetKind() != kTypeStruct) && (retType->GetKind() != kTypeUnion)) {
     return &callNode;
   }
 
diff --git a/src/mapleall/maple_be/src/cg/aarch64/aarch64_abi.cpp b/src/mapleall/maple_be/src/cg/aarch64/aarch64_abi.cpp
index 15a272e27ddcb87e0a2fb11288b701f912cce5e7..20b3fc97092dd1262f06fa59b4835e66b1c798ea 100644
--- a/src/mapleall/maple_be/src/cg/aarch64/aarch64_abi.cpp
+++ b/src/mapleall/maple_be/src/cg/aarch64/aarch64_abi.cpp
@@ -211,7 +211,7 @@ int32 ClassifyAggregate(BECommon &be, MIRType &mirType, AArch64ArgumentClass cla
   for (i = 0; i < sizeOfTyInDwords; ++i) {
     classes[i] = kAArch64NoClass;
   }
-  if ((mirType.GetKind() != kTypeStruct) && (mirType.GetKind() != kTypeArray)) {
+  if ((mirType.GetKind() != kTypeStruct) && (mirType.GetKind() != kTypeArray) && (mirType.GetKind() != kTypeUnion)) {
     return ProcessNonStructAndNonArrayWhenClassifyAggregate(mirType, classes, classesLength);
   }
   int32 subNumRegs;