diff --git a/src/system/flashtool.cpp b/src/system/flashtool.cpp
index 20447b361..2f1b576f6 100644
--- a/src/system/flashtool.cpp
+++ b/src/system/flashtool.cpp
@@ -441,10 +441,14 @@ void CFlashTool::reboot()
 }
 
 //-----------------------------------------------------------------------------------------------------------------
-CFlashVersionInfo::CFlashVersionInfo(const std::string & versionString)
+CFlashVersionInfo::CFlashVersionInfo(const std::string & _versionString)
 {
 	//SBBBYYYYMMTTHHMM -- formatsting
-
+	std::string versionString = _versionString;
+	/* just to make sure the string is long enough for the following code
+	 * trailing chars don't matter -- will just be ignored */
+	if (versionString.size() < 16)
+		versionString.append(16, '0');
 	// recover type
 	snapshot = versionString[0];