diff --git a/test/geo_alignedbox.cpp b/test/geo_alignedbox.cpp
index eca292f4c..223ff5eea 100644
--- a/test/geo_alignedbox.cpp
+++ b/test/geo_alignedbox.cpp
@@ -15,9 +15,17 @@
 #include<iostream>
 using namespace std;
 
-// TODO not sure if this is actually still necessary anywhere ...
+// NOTE the following workaround was needed on some 32 bits builds to kill extra precision of x87 registers.
+// It seems that it os not needed anymore, but let's keep it here, just in case...
+
 template<typename T> EIGEN_DONT_INLINE
-void kill_extra_precision(T& ) {  }
+void kill_extra_precision(T& /* x */) {
+  // This one worked but triggered a warning:
+  /* eigen_assert((void*)(&x) != (void*)0); */
+  // An alternative could be:
+  /* volatile T tmp = x; */
+  /* x = tmp; */
+}
 
 
 template<typename BoxType> void alignedbox(const BoxType& _box)