diff --git a/diskimg/DOS33.cpp b/diskimg/DOS33.cpp
index abe8c25..d41ad4c 100644
--- a/diskimg/DOS33.cpp
+++ b/diskimg/DOS33.cpp
@@ -2877,7 +2877,7 @@ bail:
  * If a pointer to a size_t is passed in, it will be filled with the
  * raw filename length.
  */
-const char* A2FileDOS::GetRawFileName(size_t* size = NULL) const {
+const char* A2FileDOS::GetRawFileName(size_t* size) const {
     if (size) {
         *size = strlen(fRawFileName);
     }
diff --git a/diskimg/DiskImg.cpp b/diskimg/DiskImg.cpp
index 35c372b..2404a8d 100644
--- a/diskimg/DiskImg.cpp
+++ b/diskimg/DiskImg.cpp
@@ -292,7 +292,7 @@ void DiskImg::SetCustomNibbleDescr(const NibbleDescr* pDescr)
     }
 }
 
-const char* DiskImg::GetRawFileName(size_t* size) const { // get unmodified file name
+const char* A2File::GetRawFileName(size_t* size) const { // get unmodified file name
     if (size) {
         *size = strlen(GetFileName());
     }
diff --git a/diskimg/ImageWrapper.cpp b/diskimg/ImageWrapper.cpp
index db2b203..88de58c 100644
--- a/diskimg/ImageWrapper.cpp
+++ b/diskimg/ImageWrapper.cpp
@@ -1145,7 +1145,7 @@ DIError WrapperDiskCopy42::WriteHeader(GenericFD* pGFD, const DC42Header* pHeade
      * magic string.  To be safe, we only increment it if it starts with '-'.
      * (Need access to a Macintosh to test this.)
      */
-    hdrBuf[0] = strlen(pHeader->diskName);
+    hdrBuf[0] = (uint8_t) (strlen(pHeader->diskName) % 0xff);
     if (pHeader->diskName[0] == '-' && hdrBuf[0] < (kDC42NameLen-1))
         hdrBuf[0]++;
     memcpy(&hdrBuf[1], pHeader->diskName, hdrBuf[0]);
diff --git a/diskimg/RDOS.cpp b/diskimg/RDOS.cpp
index 31574f7..7cc698e 100644
--- a/diskimg/RDOS.cpp
+++ b/diskimg/RDOS.cpp
@@ -530,7 +530,7 @@ DIError A2FileRDOS::Open(A2FileDescr** ppOpenFile, bool readOnly,
  * If a pointer to a size_t is passed in, it will be filled with the
  * raw filename length.
  */
-const char* A2FileRDOS::GetRawFileName(size_t* size = NULL) const {
+const char* A2FileRDOS::GetRawFileName(size_t* size) const {
     if (size) {
         *size = strlen(fRawFileName);
     }