diff --git a/src/app/SDCardManager.cpp b/src/app/SDCardManager.cpp
index d53e1c1..1733011 100644
--- a/src/app/SDCardManager.cpp
+++ b/src/app/SDCardManager.cpp
@@ -10,7 +10,7 @@ double SDCardManager::getSize(const SizeUnit sizeUnit)
   uint64_t numberOf512BytesChunks = blocksPerCluster() * totalClusters();//cardSize();
   double result = 0;
 
-  if(!isMounted()) return 0;
+  if(!isMounted()) return 0.0;
   
   switch(sizeUnit)
   {