diff --git a/src/fs/CFile.cpp b/src/fs/CFile.cpp
index b92d8ca..729f5fe 100644
--- a/src/fs/CFile.cpp
+++ b/src/fs/CFile.cpp
@@ -107,7 +107,7 @@ int32_t CFile::read(uint8_t *ptr, size_t size) {
     return -1;
 }
 
-int32_t CFile::write(const uint8_t *ptr, size_t size) {
+int64_t CFile::write(const uint8_t *ptr, size_t size) {
     if (iFd >= 0) {
         size_t done = 0;
         while (done < size) {
diff --git a/src/fs/CFile.hpp b/src/fs/CFile.hpp
index 34219a1..2a9cce3 100644
--- a/src/fs/CFile.hpp
+++ b/src/fs/CFile.hpp
@@ -42,7 +42,7 @@ public:
 
     int32_t read(uint8_t *ptr, size_t size);
 
-    int32_t write(const uint8_t *ptr, size_t size);
+    int64_t write(const uint8_t *ptr, size_t size);
 
     int32_t fwrite(const char *format, ...);
 
diff --git a/src/fs/FSUtils.cpp b/src/fs/FSUtils.cpp
index 283629d..b7037b5 100644
--- a/src/fs/FSUtils.cpp
+++ b/src/fs/FSUtils.cpp
@@ -132,10 +132,14 @@ int32_t FSUtils::CreateSubfolder(const char *fullpath) {
 BOOL FSUtils::saveBufferToFile(const char *path, void *buffer, uint32_t size) {
     CFile file(path, CFile::WriteOnly);
     if (!file.isOpen()) {
-        DEBUG_FUNCTION_LINE("Failed to open %s\n", path);
+        DEBUG_FUNCTION_LINE_ERR("Failed to open %s\n", path);
+        return false;
+    }
+    if (file.write((const uint8_t *) buffer, size) != size) {
+        DEBUG_FUNCTION_LINE_ERR("Failed to write file %s\n", path);
+        file.close();
         return false;
     }
-    file.write((const uint8_t *) buffer, size);
     file.close();
     return true;
 }