diff --git a/rally-jobs/extra/instance_dd_test.sh b/rally-jobs/extra/instance_dd_test.sh
index 9fc758b868..b6716e862e 100644
--- a/rally-jobs/extra/instance_dd_test.sh
+++ b/rally-jobs/extra/instance_dd_test.sh
@@ -3,7 +3,7 @@ time_seconds(){ (time -p $1 ) 2>&1 |awk '/real/{print $2}'; }
 file=/tmp/test.img
 c=100 #100M
 write_seq=$(time_seconds "dd if=/dev/zero of=$file bs=1M count=$c")
-read_seq=$(time_seconds "dd if=$file of=/dev/null bs=1M")
+read_seq=$(time_seconds "dd if=$file of=/dev/null bs=1M count=$c")
 [ -f $file ] && rm $file
 
 echo "{
diff --git a/samples/tasks/support/instance_dd_test.sh b/samples/tasks/support/instance_dd_test.sh
index 08872b6521..c48115432b 100644
--- a/samples/tasks/support/instance_dd_test.sh
+++ b/samples/tasks/support/instance_dd_test.sh
@@ -3,7 +3,7 @@ time_seconds(){ (time -p $1 ) 2>&1 |awk '/real/{print $2}'; }
 file=/tmp/test.img
 c=1000 #1GB
 write_seq_1gb=$(time_seconds "dd if=/dev/zero of=$file bs=1M count=$c")
-read_seq_1gb=$(time_seconds "dd if=$file of=/dev/null bs=1M")
+read_seq_1gb=$(time_seconds "dd if=$file of=/dev/null bs=1M count=$c")
 [ -f $file ] && rm $file
 
 echo "{