diff --git a/obabeliface/obabeliface.cpp b/obabeliface/obabeliface.cpp
index 98a9020..a168803 100644
--- a/obabeliface/obabeliface.cpp
+++ b/obabeliface/obabeliface.cpp
@@ -196,6 +196,7 @@ namespace Molsketch
 
   // TODO should be const, but OpenBabel iterator methods do not support const
   bool hasCoordinates(OpenBabel::OBMol &molecule) {
+    using namespace OpenBabel;
     FOR_ATOMS_OF_MOL(obatom, molecule) {
       if (obatom->GetVector() != OpenBabel::VZero)
         return true;