diff --git a/esp3d/src/modules/filesystem/sd/sd_native_esp8266.cpp b/esp3d/src/modules/filesystem/sd/sd_native_esp8266.cpp
index 4e449399..815969e8 100644
--- a/esp3d/src/modules/filesystem/sd/sd_native_esp8266.cpp
+++ b/esp3d/src/modules/filesystem/sd/sd_native_esp8266.cpp
@@ -154,6 +154,9 @@ uint64_t ESP_SD::totalBytes()
 
 uint64_t ESP_SD::usedBytes()
 {
+    if(freeBytes() >totalBytes() ) {
+        _sizechanged = true;
+    }
     return totalBytes() - freeBytes();
 }
 
diff --git a/esp3d/src/modules/filesystem/sd/sd_sdfat_esp32.cpp b/esp3d/src/modules/filesystem/sd/sd_sdfat_esp32.cpp
index a38d16c5..b663ed1d 100644
--- a/esp3d/src/modules/filesystem/sd/sd_sdfat_esp32.cpp
+++ b/esp3d/src/modules/filesystem/sd/sd_sdfat_esp32.cpp
@@ -144,6 +144,9 @@ uint64_t ESP_SD::totalBytes()
 
 uint64_t ESP_SD::usedBytes()
 {
+    if(freeBytes() >totalBytes() ) {
+        _sizechanged = true;
+    }
     return totalBytes() - freeBytes();
 }