diff --git a/unittests/cfdp/handler/testSourceHandler.cpp b/unittests/cfdp/handler/testSourceHandler.cpp
index 04e79713..7fbec9a1 100644
--- a/unittests/cfdp/handler/testSourceHandler.cpp
+++ b/unittests/cfdp/handler/testSourceHandler.cpp
@@ -77,6 +77,7 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
   auto genericMetadataCheck = [&](const SourceHandler::FsmResult& fsmResult,
                                   size_t expectedFileSize, uint16_t expectedSeqNum) {
     CHECK(fsmResult.errors == 0);
+    CHECK(fsmResult.callStatus == CallStatus::CALL_AGAIN);
     TmTcMessage tmtcMessage;
     const uint8_t* pduPtr;
     auto accessor = onePduSentCheck(fsmResult, tmtcMessage, &pduPtr);
@@ -111,6 +112,7 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
   auto genericEofCheck = [&](const SourceHandler::FsmResult& fsmResult, size_t expectedFileSize,
                              uint32_t expectedChecksum, uint16_t expectedSeqNum) {
     CHECK(fsmResult.errors == 0);
+    CHECK(fsmResult.callStatus == CallStatus::CALL_AGAIN);
     TmTcMessage tmtcMessage;
     const uint8_t* pduPtr;
     auto accessor = onePduSentCheck(fsmResult, tmtcMessage, &pduPtr);
@@ -132,6 +134,7 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
   };
   auto genericNoticeOfCompletionCheck = [&](const SourceHandler::FsmResult& fsmResult,
                                             uint16_t expectedSeqNum) {
+    CHECK(fsmResult.callStatus == CallStatus::DONE);
     CHECK(userMock.finishedRecvd.size() == 1);
     CHECK(userMock.finishedRecvd.back().first ==
           TransactionId(localId, TransactionSeqNum(cfdp::WidthInBytes::TWO_BYTES, expectedSeqNum)));
@@ -231,6 +234,7 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
     const uint8_t* pduPtr;
     FileDataInfo fdInfo;
     {
+      CHECK(fsmResult.callStatus == CallStatus::CALL_AGAIN);
       auto accessor = onePduSentCheck(fsmResult, tmtcMessage, &pduPtr);
       FileDataReader fdReader(pduPtr, accessor.second.size(), fdInfo);
       // 10 byte PDU header, 4 byte offset, 255 byte file data
@@ -249,18 +253,21 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
 
     // Check second file data PDU.
     sourceHandler.stateMachine();
-    auto accessor = onePduSentCheck(fsmResult, tmtcMessage, &pduPtr);
-    FileDataReader fdReader(pduPtr, accessor.second.size(), fdInfo);
-    // 10 byte PDU header, 4 byte offset, remaining file data (400 - 255 == 145).
-    CHECK(accessor.second.size() == 10 + 4 + largerFileData.size() - MAX_FILE_SEGMENT_SIZE);
-    CHECK(fdReader.parseData() == OK);
-    CHECK(fdInfo.getOffset().value() == MAX_FILE_SEGMENT_SIZE);
-    size_t fileDataSize = 0;
-    const uint8_t* fileData = fdInfo.getFileData(&fileDataSize);
-    // Maximum file segment size.
-    REQUIRE(fileDataSize == largerFileData.size() - MAX_FILE_SEGMENT_SIZE);
-    for (unsigned i = 0; i < fileDataSize; i++) {
-      CHECK(fileData[i] == largerFileData[MAX_FILE_SEGMENT_SIZE + i]);
+    {
+      CHECK(fsmResult.callStatus == CallStatus::CALL_AGAIN);
+      auto accessor = onePduSentCheck(fsmResult, tmtcMessage, &pduPtr);
+      FileDataReader fdReader(pduPtr, accessor.second.size(), fdInfo);
+      // 10 byte PDU header, 4 byte offset, remaining file data (400 - 255 == 145).
+      CHECK(accessor.second.size() == 10 + 4 + largerFileData.size() - MAX_FILE_SEGMENT_SIZE);
+      CHECK(fdReader.parseData() == OK);
+      CHECK(fdInfo.getOffset().value() == MAX_FILE_SEGMENT_SIZE);
+      size_t fileDataSize = 0;
+      const uint8_t* fileData = fdInfo.getFileData(&fileDataSize);
+      // Maximum file segment size.
+      REQUIRE(fileDataSize == largerFileData.size() - MAX_FILE_SEGMENT_SIZE);
+      for (unsigned i = 0; i < fileDataSize; i++) {
+        CHECK(fileData[i] == largerFileData[MAX_FILE_SEGMENT_SIZE + i]);
+      }
     }
     mqMock.clearMessages();