diff --git a/devel.admin.inc b/devel.admin.inc
index dbb30c9..6fec2ca 100644
--- a/devel.admin.inc
+++ b/devel.admin.inc
@@ -90,9 +90,9 @@ function devel_admin_settings() {
     '#description' => t('Display page execution time in the query log box.'),
   );
 
-  $form['dev_mem'] = array('#type' => 'checkbox',
+  $form['devel_memory'] = array('#type' => 'checkbox',
     '#title' => t('Display memory usage'),
-    '#default_value' => variable_get('dev_mem', 0),
+    '#default_value' => variable_get('devel_memory', 0),
     '#description' => t('Display how much memory is used to generate the current page. This will show memory usage when devel_init() is called and when devel_exit() is called.'),
   );
   $form['devel_redirect_page'] = array('#type' => 'checkbox',
diff --git a/devel.install b/devel.install
index 2247fa5..f082857 100644
--- a/devel.install
+++ b/devel.install
@@ -36,7 +36,7 @@ function devel_uninstall() {
   variable_del('devel_query_display');
   variable_del('devel_redirect_page');
   variable_del('devel_api_url');
-  variable_del('dev_mem');
+  variable_del('devel_memory');
   variable_del('devel_error_handlers');
   variable_del('devel_raw_names');
   variable_del('devel_switch_user_list_size');
@@ -122,3 +122,14 @@ function devel_update_7004() {
 function devel_update_7005() {
   variable_del('devel_form_weights');
 }
+
+/**
+ * Change variable 'dev_mem' to 'devel_memory'.
+ */
+function devel_update_7006() {
+  if (variable_get('dev_mem', NULL) !== NULL) {
+    variable_set('devel_memory', variable_get('dev_mem'));
+  }
+
+  variable_del('dev_mem');
+}
diff --git a/devel.module b/devel.module
index 2554cd1..1722d02 100644
--- a/devel.module
+++ b/devel.module
@@ -632,7 +632,7 @@ function devel_boot() {
   devel_xhprof_enable();
 
   if (!devel_silent()) {
-    if (variable_get('dev_mem', 0)) {
+    if (variable_get('devel_memory', 0)) {
       global $memory_init;
       $memory_init = memory_get_usage();
     }
@@ -1218,7 +1218,7 @@ function devel_xhprof_link($run_id, $type = 'link') {
 function devel_shutdown_memory() {
   global $memory_init;
 
-  if (variable_get('dev_mem', FALSE)) {
+  if (variable_get('devel_memory', FALSE)) {
     $memory_shutdown = memory_get_usage();
     $args = array(
       '@memory_boot' => round($memory_init / 1024 / 1024, 2),