diff --git a/common/io/io_base.cpp b/common/io/io_base.cpp
index 722986af4c..b099d9045a 100644
--- a/common/io/io_base.cpp
+++ b/common/io/io_base.cpp
@@ -76,7 +76,7 @@ bool IO_BASE::CanReadLibrary( const wxString& aFileName ) const
     {
         const std::vector<std::string>& exts = desc.m_FileExtensions;
 
-        wxString fileExt = wxFileName( aFileName ).GetExt().MakeLower();
+        wxString fileExt = wxFileName( aFileName ).GetExt().Lower();
 
         for( const std::string& ext : exts )
         {