diff --git a/src/fsfw/cfdp/definitions.h b/src/fsfw/cfdp/definitions.h
index e5c11a0b..35c4c5f8 100644
--- a/src/fsfw/cfdp/definitions.h
+++ b/src/fsfw/cfdp/definitions.h
@@ -20,7 +20,7 @@ static constexpr uint8_t VERSION_BITS = CFDP_VERSION_2 << 5;
 static constexpr uint8_t CFDP_CLASS_ID = CLASS_ID::CFDP;
 
 static constexpr ReturnValue_t INVALID_TLV_TYPE = returnvalue::makeCode(CFDP_CLASS_ID, 1);
-static constexpr ReturnValue_t INVALID_DIRECTIVE_FIELDS = returnvalue::makeCode(CFDP_CLASS_ID, 2);
+static constexpr ReturnValue_t INVALID_DIRECTIVE_FIELD = returnvalue::makeCode(CFDP_CLASS_ID, 2);
 static constexpr ReturnValue_t INVALID_PDU_DATAFIELD_LEN = returnvalue::makeCode(CFDP_CLASS_ID, 3);
 static constexpr ReturnValue_t INVALID_ACK_DIRECTIVE_FIELDS =
     returnvalue::makeCode(CFDP_CLASS_ID, 4);
@@ -30,13 +30,14 @@ static constexpr ReturnValue_t METADATA_CANT_PARSE_OPTIONS =
     returnvalue::makeCode(CFDP_CLASS_ID, 5);
 static constexpr ReturnValue_t NAK_CANT_PARSE_OPTIONS = returnvalue::makeCode(CFDP_CLASS_ID, 6);
 static constexpr ReturnValue_t FINISHED_CANT_PARSE_FS_RESPONSES =
-    returnvalue::makeCode(CFDP_CLASS_ID, 6);
+    returnvalue::makeCode(CFDP_CLASS_ID, 7);
 static constexpr ReturnValue_t FILESTORE_REQUIRES_SECOND_FILE =
     returnvalue::makeCode(CFDP_CLASS_ID, 8);
 //! Can not parse filestore response because user did not pass a valid instance
 //! or remaining size is invalid
 static constexpr ReturnValue_t FILESTORE_RESPONSE_CANT_PARSE_FS_MESSAGE =
     returnvalue::makeCode(CFDP_CLASS_ID, 9);
+static constexpr ReturnValue_t INVALID_PDU_FORMAT = returnvalue::makeCode(CFDP_CLASS_ID, 10);
 
 //! Checksum types according to the SANA Checksum Types registry
 //! https://sanaregistry.org/r/checksum_identifiers/
@@ -71,6 +72,7 @@ enum WidthInBytes : uint8_t {
 
 enum FileDirectives : uint8_t {
   INVALID_DIRECTIVE = 0x0f,
+  // The _DIRECTIVE suffix is mandatory here because of some nameclash!
   EOF_DIRECTIVE = 0x04,
   FINISH = 0x05,
   ACK = 0x06,
diff --git a/src/fsfw/cfdp/handler/DestHandler.h b/src/fsfw/cfdp/handler/DestHandler.h
index 8a8dd28e..000fc2c0 100644
--- a/src/fsfw/cfdp/handler/DestHandler.h
+++ b/src/fsfw/cfdp/handler/DestHandler.h
@@ -62,9 +62,9 @@ struct DestHandlerParams {
 };
 
 struct FsfwParams {
-
   FsfwParams(AcceptsTelemetryIF& packetDest, MessageQueueIF* msgQueue,
-             EventReportingProxyIF* eventReporter, StorageManagerIF& tcStore, StorageManagerIF& tmStore)
+             EventReportingProxyIF* eventReporter, StorageManagerIF& tcStore,
+             StorageManagerIF& tmStore)
       : FsfwParams(packetDest, msgQueue, eventReporter) {
     this->tcStore = &tcStore;
     this->tmStore = &tmStore;
diff --git a/src/fsfw/cfdp/pdu/FileDirectiveReader.cpp b/src/fsfw/cfdp/pdu/FileDirectiveReader.cpp
index 5d43ebb0..748ac830 100644
--- a/src/fsfw/cfdp/pdu/FileDirectiveReader.cpp
+++ b/src/fsfw/cfdp/pdu/FileDirectiveReader.cpp
@@ -18,7 +18,7 @@ ReturnValue_t FileDirectiveReader::parseData() {
   }
   size_t currentIdx = PduHeaderReader::getHeaderSize();
   if (not checkFileDirective(pointers.rawPtr[currentIdx])) {
-    return cfdp::INVALID_DIRECTIVE_FIELDS;
+    return cfdp::INVALID_DIRECTIVE_FIELD;
   }
   setFileDirective(static_cast<cfdp::FileDirectives>(pointers.rawPtr[currentIdx]));
   return returnvalue::OK;
@@ -32,7 +32,7 @@ size_t FileDirectiveReader::getHeaderSize() const {
 bool FileDirectiveReader::checkFileDirective(uint8_t rawByte) {
   if (rawByte < cfdp::FileDirectives::EOF_DIRECTIVE or
       (rawByte > cfdp::FileDirectives::PROMPT and rawByte != cfdp::FileDirectives::KEEP_ALIVE)) {
-    // Invalid directive field. TODO: Custom returnvalue
+    // Invalid directive field
     return false;
   }
   return true;
diff --git a/src/fsfw/cfdp/pdu/FileDirectiveReader.h b/src/fsfw/cfdp/pdu/FileDirectiveReader.h
index 83a71c71..5bec486c 100644
--- a/src/fsfw/cfdp/pdu/FileDirectiveReader.h
+++ b/src/fsfw/cfdp/pdu/FileDirectiveReader.h
@@ -26,10 +26,9 @@ class FileDirectiveReader : public PduHeaderReader {
 
   void setEndianness(SerializeIF::Endianness endianness);
   [[nodiscard]] SerializeIF::Endianness getEndianness() const;
-
- protected:
   static bool checkFileDirective(uint8_t rawByte);
 
+ protected:
  private:
   void setFileDirective(cfdp::FileDirectives fileDirective);
   cfdp::FileDirectives fileDirective = cfdp::FileDirectives::INVALID_DIRECTIVE;
diff --git a/unittests/cfdp/pdu/testAckPdu.cpp b/unittests/cfdp/pdu/testAckPdu.cpp
index 1eb1b340..02832d9f 100644
--- a/unittests/cfdp/pdu/testAckPdu.cpp
+++ b/unittests/cfdp/pdu/testAckPdu.cpp
@@ -91,7 +91,7 @@ TEST_CASE("ACK PDU", "[cfdp][pdu]") {
     buf[sz - 2] = prevVal;
     buf[sz - 3] = cfdp::FileDirectives::INVALID_DIRECTIVE;
     result = reader2.parseData();
-    REQUIRE(result == cfdp::INVALID_DIRECTIVE_FIELDS);
+    REQUIRE(result == cfdp::INVALID_DIRECTIVE_FIELD);
     buf[sz - 3] = cfdp::FileDirectives::ACK;
     auto maxSizeTooSmall = AckPduDeserializer(buf.data(), sz - 2, ackInfo2);
     result = maxSizeTooSmall.parseData();
diff --git a/unittests/cfdp/pdu/testFileDirective.cpp b/unittests/cfdp/pdu/testFileDirective.cpp
index cb1df08d..31e627a6 100644
--- a/unittests/cfdp/pdu/testFileDirective.cpp
+++ b/unittests/cfdp/pdu/testFileDirective.cpp
@@ -80,6 +80,6 @@ TEST_CASE("CFDP File Directive", "[cfdp][pdu]") {
 
     serBuf[7] = 0xff;
     // Invalid file directive
-    REQUIRE(fdDeser.parseData() == cfdp::INVALID_DIRECTIVE_FIELDS);
+    REQUIRE(fdDeser.parseData() == cfdp::INVALID_DIRECTIVE_FIELD);
   }
 }
\ No newline at end of file
diff --git a/unittests/cfdp/testCfdp.cpp b/unittests/cfdp/testCfdp.cpp
index 2e493539..38504a5b 100644
--- a/unittests/cfdp/testCfdp.cpp
+++ b/unittests/cfdp/testCfdp.cpp
@@ -72,7 +72,7 @@ TEST_CASE("CFDP Base", "[cfdp]") {
 
     serBuf[7] = 0xff;
     // Invalid file directive
-    REQUIRE(fdDeser.parseData() == cfdp::INVALID_DIRECTIVE_FIELDS);
+    REQUIRE(fdDeser.parseData() == cfdp::INVALID_DIRECTIVE_FIELD);
   }
 
   SECTION("File Size") {