diff --git a/debian/changelog b/debian/changelog
index 53878de..92881b9 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -8,7 +8,7 @@ rpi-imager (1.7.4) unstable; urgency=medium
     disk device, without having to rely on the operating system
     to mount the partition first.
 
- -- Floris Bos <bos@je-eigen-domein.nl>  Mon, 14 Nov 2022 21:49:27 +0100
+ -- Floris Bos <bos@je-eigen-domein.nl>  Sun, 20 Nov 2022 17:30:20 +0100
 
 rpi-imager (1.7.3) unstable; urgency=medium
 
diff --git a/src/devicewrapperfatpartition.cpp b/src/devicewrapperfatpartition.cpp
index cd5e1c5..a05d2c4 100644
--- a/src/devicewrapperfatpartition.cpp
+++ b/src/devicewrapperfatpartition.cpp
@@ -506,6 +506,8 @@ void DeviceWrapperFatPartition::updateDirEntry(struct dir_entry *dirEntry)
     struct dir_entry iterEntry;
 
     openDir();
+    quint64 oldOffset = _offset;
+
     while (readDir(&iterEntry))
     {
         /* Look for existing entry with same short filename */
@@ -513,10 +515,12 @@ void DeviceWrapperFatPartition::updateDirEntry(struct dir_entry *dirEntry)
                 && memcmp(dirEntry->DIR_Name, iterEntry.DIR_Name, sizeof(iterEntry.DIR_Name)) == 0)
         {
             /* seek() back and write out new entry */
-            _offset -= sizeof(*dirEntry);
+            _offset = oldOffset;
             write((char *) dirEntry, sizeof(*dirEntry));
             return;
         }
+
+        oldOffset = _offset;
     }
 
     throw std::runtime_error("Error locating existing directory entry");
@@ -524,6 +528,7 @@ void DeviceWrapperFatPartition::updateDirEntry(struct dir_entry *dirEntry)
 
 void DeviceWrapperFatPartition::writeDirEntryAtCurrentPos(struct dir_entry *dirEntry)
 {
+    //qDebug() << "Write new entry" << QByteArray((char *) dirEntry->DIR_Name, 11);
     write((char *) dirEntry, sizeof(*dirEntry));
 
     if (_type == FAT32)
@@ -532,15 +537,23 @@ void DeviceWrapperFatPartition::writeDirEntryAtCurrentPos(struct dir_entry *dirE
         {
             /* We reached the end of the cluster, allocate/seek to next cluster */
             uint32_t nextCluster = getFAT(_fat32_currentRootDirCluster);
-            /* FIXME: should we check for circular cluster references? */
 
             if (nextCluster > 0xFFFFFF7)
             {
                 nextCluster = allocateCluster(_fat32_currentRootDirCluster);
             }
 
+            if (_currentDirClusters.contains(nextCluster))
+                throw std::runtime_error("Circular cluster references in FAT32 directory detected");
+            _currentDirClusters.append(nextCluster);
+
             _fat32_currentRootDirCluster = nextCluster;
             seekCluster(_fat32_currentRootDirCluster);
+
+            /* Zero out entire new cluster, as fsck.fat does not stop reading entries at end-of-directory marker */
+            QByteArray zeroes(_bytesPerCluster, 0);
+            write(zeroes.data(), zeroes.length() );
+            seekCluster(_fat32_currentRootDirCluster);
         }
     }
     else if (pos() > (_fat16_firstRootDirSector+_fat16_rootDirSectors)*_bytesPerSector)
@@ -560,6 +573,10 @@ void DeviceWrapperFatPartition::openDir()
     {
         _fat32_currentRootDirCluster = _fat32_firstRootDirCluster;
         seekCluster(_fat32_currentRootDirCluster);
+        /* Keep track of directory clusters we seeked to, to be able
+           to detect circular references */
+        _currentDirClusters.clear();
+        _currentDirClusters.append(_fat32_currentRootDirCluster);
     }
 }
 
@@ -581,11 +598,13 @@ bool DeviceWrapperFatPartition::readDir(struct dir_entry *result)
         {
             /* We reached the end of the cluster, seek to next cluster */
             uint32_t nextCluster = getFAT(_fat32_currentRootDirCluster);
-            /* FIXME: should we check for circular cluster references? */
 
             if (nextCluster > 0xFFFFFF7)
                 throw std::runtime_error("Reached end of FAT32 root directory, but no end-of-directory marker found");
 
+            if (_currentDirClusters.contains(nextCluster))
+                throw std::runtime_error("Circular cluster references in FAT32 directory detected");
+            _currentDirClusters.append(nextCluster);
             _fat32_currentRootDirCluster = nextCluster;
             seekCluster(_fat32_currentRootDirCluster);
         }
diff --git a/src/devicewrapperfatpartition.h b/src/devicewrapperfatpartition.h
index ed22afc..0c7496b 100644
--- a/src/devicewrapperfatpartition.h
+++ b/src/devicewrapperfatpartition.h
@@ -31,6 +31,7 @@ protected:
     uint32_t _fat32_firstRootDirCluster, _fat32_currentRootDirCluster;
     uint16_t _bytesPerSector, _fat32_fsinfoSector;
     QList<uint32_t> _fatStartOffset;
+    QList<uint32_t> _currentDirClusters;
 
     QList<uint32_t> getClusterChain(uint32_t firstCluster);
     void setFAT16(uint16_t cluster, uint16_t value);