diff --git a/diskimg/ProDOS.cpp b/diskimg/ProDOS.cpp
index b848822..90d604d 100644
--- a/diskimg/ProDOS.cpp
+++ b/diskimg/ProDOS.cpp
@@ -4538,6 +4538,8 @@ DIError A2FDProDOS::Write(const void* buf, size_t len, size_t* pActual)
     bool allocSparse = (pDiskFS->GetParameter(DiskFS::kParmProDOS_AllocSparse) != 0);
     uint8_t blkBuf[kBlkSize];
     uint16_t keyBlock;
+    bool allZero = true;
+    const uint8_t* scanPtr = (const uint8_t*)buf;
 
     if (len >= 0x01000000) {    // 16MB
         assert(false);
@@ -4578,8 +4580,6 @@ DIError A2FDProDOS::Write(const void* buf, size_t len, size_t* pActual)
      * where we store it as a seedling.  (GS/OS seems to do this, ProDOS 8
      * v2.0.3 tends to allocate the first block.)
      */
-    bool allZero = true;
-    const uint8_t* scanPtr = (const uint8_t*)buf;
     for (unsigned int i = 0; i < len; ++i, ++scanPtr) {
         if (*scanPtr != 0x00) {
             allZero = false;
diff --git a/diskimg/TwoImg.cpp b/diskimg/TwoImg.cpp
index 9d21cb0..e42499a 100644
--- a/diskimg/TwoImg.cpp
+++ b/diskimg/TwoImg.cpp
@@ -30,7 +30,7 @@ int TwoImgHeader::InitHeader(int imageFormat, uint32_t imageSize,
 {
     if (imageSize == 0)
         return -1;
-    if (imageFormat < kImageFormatDOS || imageFormat > (int) kImageFormatNibble)
+    if (imageFormat < (int) kImageFormatDOS || imageFormat > (int) kImageFormatNibble)
         return -1;
 
     if (imageFormat != kImageFormatNibble &&