diff --git a/tools/cli-video/appl/main-tool-client-video.cpp b/tools/cli-video/appl/main-tool-client-video.cpp
index e5ddc26..986bc0b 100644
--- a/tools/cli-video/appl/main-tool-client-video.cpp
+++ b/tools/cli-video/appl/main-tool-client-video.cpp
@@ -56,7 +56,7 @@ bool pushVideoFile(zeus::service::ProxyVideo& _srv, etk::String _path, etk::Map<
 	etk::String extention;
 	if (    _path.rfind('.') != etk::String::npos
 	     && _path.rfind('.') != 0) {
-		extention = etk::tolower(etk::String(_path.begin()+_path.rfind('.')+1, _path.end()));
+		extention = etk::toLower(etk::String(_path.begin()+_path.rfind('.')+1, _path.end()));
 	}
 	etk::String fileName = etk::split(_path, '/').back();
 	// internal extention ...
diff --git a/zeus/mineType.cpp b/zeus/mineType.cpp
index 7df697c..4621f71 100644
--- a/zeus/mineType.cpp
+++ b/zeus/mineType.cpp
@@ -188,7 +188,7 @@ static etk::Vector<etk::Pair<etk::String, etk::String>> getMimeList() {
 };
 
 etk::String zeus::getMineType(etk::String _extention) {
-	_extention = etk::tolower(_extention);
+	_extention = etk::toLower(_extention);
 	for (auto &it : getMimeList()) {
 		if (it.first == _extention) {
 			return it.second;
@@ -201,7 +201,7 @@ etk::String zeus::getMineType(etk::String _extention) {
 }
 
 etk::String zeus::getExtention(etk::String _mineType) {
-	_mineType = etk::tolower(_mineType);
+	_mineType = etk::toLower(_mineType);
 	for (auto &it : getMimeList()) {
 		if (it.second == _mineType) {
 			return it.first;
diff --git a/zeus/zeus-Media.impl.cpp b/zeus/zeus-Media.impl.cpp
index 6920cf8..7aee1bc 100644
--- a/zeus/zeus-Media.impl.cpp
+++ b/zeus/zeus-Media.impl.cpp
@@ -62,7 +62,7 @@ zeus::MediaImpl::MediaImpl(uint64_t _id, const etk::String& _fileNameReal, const
 	etk::String extention;
 	if (    m_fileName.rfind('.') != etk::String::npos
 	     && m_fileName.rfind('.') != 0) {
-		extention = etk::tolower(etk::String(m_fileName.begin()+m_fileName.rfind('.')+1, m_fileName.end()));
+		extention = etk::toLower(etk::String(m_fileName.begin()+m_fileName.rfind('.')+1, m_fileName.end()));
 		m_fileName = etk::String(m_fileName.begin(), m_fileName.begin()+m_fileName.rfind('.'));
 	}
 	if (extention != "") {