diff --git a/CHANGELOG.md b/CHANGELOG.md
index 834ec9a..c43c4d3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -49,6 +49,12 @@
   `PLDM_INVALID_TRANSFER_OPERATION_FLAG` in `encode_pass_component_table_req()`
   command.
 
+- base: Return valid completion code from `decode_multipart_receive_req()`
+
+  As per the base specification `PLDM_INVALID_TRANSFER_OPERATION_FLAG` (`0x21`)
+  is inaccurate. Reduce the usage of it by returning
+  `PLDM_ERROR_UNEXPECTED_TRANSFER_FLAG_OPERATION` (code 0x23) instead.
+
 ### Deprecated
 
 - utils: Deprecate `is_time_legal()`
diff --git a/src/dsp/base.c b/src/dsp/base.c
index 1b16381..c3a5ed9 100644
--- a/src/dsp/base.c
+++ b/src/dsp/base.c
@@ -552,7 +552,7 @@
 
 	// Any enum value above PLDM_XFER_CURRENT_PART is invalid.
 	if (request->transfer_opflag > PLDM_XFER_CURRENT_PART) {
-		return PLDM_INVALID_TRANSFER_OPERATION_FLAG;
+		return PLDM_ERROR_UNEXPECTED_TRANSFER_FLAG_OPERATION;
 	}
 
 	// A section offset of 0 is only valid on FIRST_PART or COMPLETE Xfers.
diff --git a/tests/dsp/base.cpp b/tests/dsp/base.cpp
index 25536ec..c544766 100644
--- a/tests/dsp/base.cpp
+++ b/tests/dsp/base.cpp
@@ -686,7 +686,7 @@
                                            &pldm_type, &flag, &transfer_ctx,
                                            &transfer_handle, &section_offset,
                                            &section_length),
-              PLDM_INVALID_TRANSFER_OPERATION_FLAG);
+              PLDM_ERROR_UNEXPECTED_TRANSFER_FLAG_OPERATION);
 }
 
 TEST(MultipartReceive, testDecodeRequestFailBadOffset)