diff --git a/tests/common/multithread-locking-test.cpp b/tests/common/multithread-locking-test.cpp
index d03fe5c28..465929e55 100644
--- a/tests/common/multithread-locking-test.cpp
+++ b/tests/common/multithread-locking-test.cpp
@@ -56,8 +56,8 @@ namespace lib {
       
       class Victim
         {
-          long cnt_[NUM_COUNTERS];
-          uint step_;         ///< @note stored as instance variable
+          volatile long cnt_[NUM_COUNTERS];
+          volatile uint step_;         ///< @note stored as instance variable
 
           void
           pause ()