diff --git a/libatomic_ops/tests/test_atomic.c b/libatomic_ops/tests/test_atomic.c

index e354024..b8906e9 100644

--- a/libatomic_ops/tests/test_atomic.c

+++ b/libatomic_ops/tests/test_atomic.c

@@ -77,7 +77,10 @@ void * acqrel_thr(void *id)

       {

         AO_t my_counter1;

     if (me != 1)

-      fprintf(stderr, "acqrel test: too many threads\n");

+      {

+        fprintf(stderr, "acqrel test: too many threads\n");

+        abort();

+      }

     my_counter1 = AO_load(&counter1);

     AO_store(&counter1, my_counter1 + 1);

     AO_store_release_write(&counter2, my_counter1 + 1);

diff --git a/libatomic_ops/tests/test_malloc.c b/libatomic_ops/tests/test_malloc.c

index a1f4179..a19ffd5 100644

--- a/libatomic_ops/tests/test_malloc.c

+++ b/libatomic_ops/tests/test_malloc.c

@@ -151,6 +151,7 @@ void * run_one_test(void * arg) {

   if (0 == p) {

 #   ifdef HAVE_MMAP

       fprintf(stderr, "AO_malloc(%d) failed\n", LARGE_OBJ_SIZE);

+      abort();

 #   else

       fprintf(stderr, "AO_malloc(%d) failed: This is normal without mmap\n",

               LARGE_OBJ_SIZE);

diff --git a/libatomic_ops/tests/test_stack.c b/libatomic_ops/tests/test_stack.c

index bf3180d..e654c35 100644

--- a/libatomic_ops/tests/test_stack.c

+++ b/libatomic_ops/tests/test_stack.c

@@ -97,14 +97,23 @@ void check_list(int n)

        p = (list_element *)AO_REAL_NEXT_PTR(p -> next))

     {

       if (p -> data > n || p -> data <= 0)

-        fprintf(stderr, "Found erroneous list element %d\n", p -> data);

+        {

+          fprintf(stderr, "Found erroneous list element %d\n", i);

+          abort();

+        }

       if (marks[p -> data] != 0)

-        fprintf(stderr, "Found duplicate list element %d\n", p -> data);

+        {

+          fprintf(stderr, "Found duplicate list element %d\n", i);

+          abort();

+        }

       marks[p -> data] = 1;

     }

   for (i = 1; i <= n; ++i)

     if (marks[i] != 1)

-      fprintf(stderr, "Missing list element %d\n", i);

+      {

+        fprintf(stderr, "Missing list element %d\n", i);

+        abort();

+      }

 }

 volatile AO_t ops_performed = 0;

@@ -218,6 +227,7 @@ int main(int argc, char **argv)

           int code;

           if ((code = pthread_join(thread[i], 0)) != 0) {

             fprintf(stderr, "Thread join failed %u\n", code);

+            abort();

           }

         }

         times[nthreads][exper_n] = (unsigned long)(get_msecs() - start_time);