diff --git a/exp-drd/tests/tc20_verifywrap2.stderr.exp-glibc2.3 b/exp-drd/tests/tc20_verifywrap2.stderr.exp-glibc2.3
index 221e93748..af6a443db 100644
--- a/exp-drd/tests/tc20_verifywrap2.stderr.exp-glibc2.3
+++ b/exp-drd/tests/tc20_verifywrap2.stderr.exp-glibc2.3
@@ -18,7 +18,7 @@ Other segment end (thread 0/2)
 
 [1/1] mutex_init      invalid mutex 0x........
 
-Not a mutex
+The object at address 0x........ is not a mutex.
    at 0x........: pthread_mutex_init (drd_pthread_intercepts.c:?)
    by 0x........: main (tc20_verifywrap.c:92)
 [1/1] mutex_init      mutex 0x........
@@ -34,19 +34,19 @@ make pthread_mutex_lock fail: skipped on glibc < 2.4
 
 [1/1] pre_mutex_lock  invalid mutex 0x........ rc 0 owner 0
 
-Not a mutex
+The object at address 0x........ is not a mutex.
    at 0x........: pthread_mutex_trylock (drd_pthread_intercepts.c:?)
    by 0x........: main (tc20_verifywrap.c:116)
 [1/1] post_mutex_lock invalid mutex 0x........ rc 0 owner 0
 [1/1] pre_mutex_lock  invalid mutex 0x........ rc 0 owner 0
 
-Not a mutex
+The object at address 0x........ is not a mutex.
    at 0x........: pthread_mutex_timedlock (drd_pthread_intercepts.c:?)
    by 0x........: main (tc20_verifywrap.c:121)
 [1/1] post_mutex_lock invalid mutex 0x........ rc 0 owner 0
 [1/1] mutex_unlock    invalid mutex 0x........ rc 0
 
-Not a mutex
+The object at address 0x........ is not a mutex.
    at 0x........: pthread_mutex_unlock (drd_pthread_intercepts.c:?)
    by 0x........: main (tc20_verifywrap.c:125)