diff --git a/fastboot/device/flashing.cpp b/fastboot/device/flashing.cpp
index 06ffe0f..05186a2 100644
--- a/fastboot/device/flashing.cpp
+++ b/fastboot/device/flashing.cpp
@@ -121,7 +121,12 @@
 int WriteCallback(void* priv, const void* data, size_t len) {
     PartitionHandle* handle = reinterpret_cast<PartitionHandle*>(priv);
     if (!data) {
-        return lseek64(handle->fd(), len, SEEK_CUR) >= 0 ? 0 : -errno;
+        if (lseek64(handle->fd(), len, SEEK_CUR) < 0) {
+            int rv = -errno;
+            PLOG(ERROR) << "lseek failed";
+            return rv;
+        }
+        return 0;
     }
     return FlashRawDataChunk(handle, reinterpret_cast<const char*>(data), len);
 }
@@ -131,6 +136,7 @@
                                                       downloaded_data.size(), true, false);
     if (!file) {
         // Invalid sparse format
+        LOG(ERROR) << "Unable to open sparse data for flashing";
         return -EINVAL;
     }
     return sparse_file_callback(file, false, false, WriteCallback, reinterpret_cast<void*>(handle));
@@ -175,10 +181,13 @@
 
     std::vector<char> data = std::move(device->download_data());
     if (data.size() == 0) {
+        LOG(ERROR) << "Cannot flash empty data vector";
         return -EINVAL;
     }
     uint64_t block_device_size = get_block_device_size(handle.fd());
     if (data.size() > block_device_size) {
+        LOG(ERROR) << "Cannot flash " << data.size() << " bytes to block device of size "
+                   << block_device_size;
         return -EOVERFLOW;
     } else if (data.size() < block_device_size &&
                (partition_name == "boot" || partition_name == "boot_a" ||
diff --git a/fastboot/device/main.cpp b/fastboot/device/main.cpp
index df9c900..08c9358 100644
--- a/fastboot/device/main.cpp
+++ b/fastboot/device/main.cpp
@@ -14,13 +14,30 @@
  * limitations under the License.
  */
 
+#include <stdarg.h>
+
 #include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+#include <sparse/sparse.h>
 
 #include "fastboot_device.h"
 
+static void LogSparseVerboseMessage(const char* fmt, ...) {
+    std::string message;
+
+    va_list ap;
+    va_start(ap, fmt);
+    android::base::StringAppendV(&message, fmt, ap);
+    va_end(ap);
+
+    LOG(ERROR) << "libsparse message: " << message;
+}
+
 int main(int /*argc*/, char* argv[]) {
     android::base::InitLogging(argv, &android::base::KernelLogger);
 
+    sparse_print_verbose = LogSparseVerboseMessage;
+
     while (true) {
         FastbootDevice device;
         device.ExecuteCommands();