diff --git a/tests/1_host_configuration.sh b/tests/1_host_configuration.sh
index 42ca105..6e2b66d 100644
--- a/tests/1_host_configuration.sh
+++ b/tests/1_host_configuration.sh
@@ -39,8 +39,8 @@ fi
 
 # 1.6
 check_1_6="1.6  - Keep Docker up to date"
+docker_version=$(docker version | grep 'Server version' | awk '{print $3}')
 do_version_check 1.6.2 $docker_version
-docker version | grep 'Server version' | awk '{print $3}'
 if [ $? -eq 11 ]; then
   warn "$check_1_6"
 else
diff --git a/tests/2_docker_daemon_configuration.sh b/tests/2_docker_daemon_configuration.sh
index cde2345..8561f52 100644
--- a/tests/2_docker_daemon_configuration.sh
+++ b/tests/2_docker_daemon_configuration.sh
@@ -60,7 +60,7 @@ fi
 
 # 2.7
 check_2_7="2.7  - Do not use the aufs storage driver"
-docker info 2>/dev/null| grep -e "^Storage Driver:\s*aufs\s*$"
+docker info 2>/dev/null | grep -e "^Storage Driver:\s*aufs\s*$" >/dev/null 2>&1
 if [ $? -eq 0 ]; then
   warn "$check_2_7"
 else
diff --git a/tests/5_container_runtime.sh b/tests/5_container_runtime.sh
index a9ff634..11e14df 100644
--- a/tests/5_container_runtime.sh
+++ b/tests/5_container_runtime.sh
@@ -64,7 +64,7 @@ else
     exec_check=$(docker exec "$c" ps -el 2>/dev/null)
     if [ $? -eq 255 ]; then
       warn "$check_5_3"
-      warn "      * Docker exec fails: $c"
+      warn "     * Docker exec fails: $c"
       fail=1
     fi
 
@@ -172,10 +172,10 @@ else
 
   fail=0
   for c in $containers; do
-    docker exec "$c" ps -el 2>/dev/null
+    exec_check=$(docker exec "$c" ps -el 2>/dev/null)
     if [ $? -eq 255 ]; then
       warn "$check_5_7"
-      warn "     * Docker exec failed: $c"
+      warn "     * Docker exec fails: $c"
       fail=1
     fi
 
diff --git a/tests/6_docker_security_operations.sh b/tests/6_docker_security_operations.sh
index d1191b5..f5b1f01 100644
--- a/tests/6_docker_security_operations.sh
+++ b/tests/6_docker_security_operations.sh
@@ -36,7 +36,15 @@ set +f; unset IFS
 
 # 6.6
 check_6_6="6.6 - Avoid image sprawl"
-images=$(docker images | wc -l | awk '{print $1}')
+images=$(docker images -q | wc -l | awk '{print $1}')
+active_images=0
+
+for c in $(docker inspect -f "{{.Image}}" $(docker ps -qa)); do
+  if [[ $(docker images --no-trunc -a | grep $c) ]]; then
+    ((active_images++))
+  fi
+done
+
 if [ "$images" -gt 100 ]; then
   warn "$check_6_6"
   warn "     * There are currently: $images images"
@@ -45,6 +53,10 @@ else
   info "     * There are currently: $images images"
 fi
 
+if [[ "$active_images" -lt "$((images / 2))" ]]; then
+  warn "     * Only $active_images out of $images are in use"
+fi
+
 # 6.7
 check_6_7="6.7 - Avoid container sprawl"
 total_containers=$(docker info 2>/dev/null | grep "Containers" | awk '{print $2}')