Index: kernel/include/IMP/internal/Unit.h
===================================================================
--- kernel/include/IMP/internal/Unit.h	(revision 611)
+++ kernel/include/IMP/internal/Unit.h	(working copy)
@@ -338,7 +338,7 @@
 Unit<Tag, EXP/2, typename internal::Sqrt<Units>::type >
 sqrt(Unit<Tag, EXP, Units> o) {
   return Unit<Tag, EXP/2, typename internal::Sqrt<Units>::type >
-    (ExponentialNumber<EXP/2>(std::sqrt(o.get_normalized_value())));
+    (ExponentialNumber<EXP/2>(std::sqrt(o.get_value())));
 }
 
 /** \internal