diff --git a/recovery.cpp b/recovery.cpp
index cf368e4..c681c8c 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -75,6 +75,7 @@
   { "stages", required_argument, NULL, 'g' },
   { "shutdown_after", no_argument, NULL, 'p' },
   { "reason", required_argument, NULL, 'r' },
+  { "security", no_argument, NULL, 'e'},
   { NULL, 0, NULL, 0 },
 };
 
@@ -1328,6 +1329,7 @@
     bool just_exit = false;
     bool shutdown_after = false;
     int retry_count = 0;
+    bool security_update = false;
 
     int arg;
     while ((arg = getopt_long(argc, argv, "", OPTIONS, NULL)) != -1) {
@@ -1351,6 +1353,7 @@
         }
         case 'p': shutdown_after = true; break;
         case 'r': reason = optarg; break;
+        case 'e': security_update = true; break;
         case '?':
             LOGE("Invalid command argument\n");
             continue;
@@ -1370,6 +1373,9 @@
 
     ui->SetLocale(locale);
     ui->Init();
+    // Set background string to "installing security update" for security update,
+    // otherwise set it to "installing system update".
+    ui->SetSystemUpdateText(security_update);
 
     int st_cur, st_max;
     if (stage != NULL && sscanf(stage, "%d/%d", &st_cur, &st_max) == 2) {
diff --git a/screen_ui.cpp b/screen_ui.cpp
index cd3671f..3697554 100644
--- a/screen_ui.cpp
+++ b/screen_ui.cpp
@@ -425,6 +425,16 @@
     return result;
 }
 
+// Choose the right background string to display during update.
+void ScreenRecoveryUI::SetSystemUpdateText(bool security_update) {
+    if (security_update) {
+        LoadLocalizedBitmap("installing_security_text", &installing_text);
+    } else {
+        LoadLocalizedBitmap("installing_text", &installing_text);
+    }
+    Redraw();
+}
+
 void ScreenRecoveryUI::Init() {
     gr_init();
 
@@ -450,7 +460,10 @@
     LoadBitmap("stage_empty", &stageMarkerEmpty);
     LoadBitmap("stage_fill", &stageMarkerFill);
 
-    LoadLocalizedBitmap("installing_text", &installing_text);
+    // Background text for "installing_update" could be "installing update"
+    // or "installing security update". It will be set after UI init according
+    // to commands in BCB.
+    installing_text = nullptr;
     LoadLocalizedBitmap("erasing_text", &erasing_text);
     LoadLocalizedBitmap("no_command_text", &no_command_text);
     LoadLocalizedBitmap("error_text", &error_text);
diff --git a/screen_ui.h b/screen_ui.h
index d8ac85b..4319b76 100644
--- a/screen_ui.h
+++ b/screen_ui.h
@@ -34,6 +34,7 @@
 
     // overall recovery state ("background image")
     void SetBackground(Icon icon);
+    void SetSystemUpdateText(bool security_update);
 
     // progress indicator
     void SetProgressType(ProgressType type);
diff --git a/tests/component/verifier_test.cpp b/tests/component/verifier_test.cpp
index 6a5e369..d7166df 100644
--- a/tests/component/verifier_test.cpp
+++ b/tests/component/verifier_test.cpp
@@ -46,6 +46,7 @@
     void SetStage(int, int) { }
     void SetLocale(const char*) { }
     void SetBackground(Icon /*icon*/) { }
+    void SetSystemUpdateText(bool /*security_update*/) { }
 
     void SetProgressType(ProgressType /*determinate*/) { }
     void ShowProgress(float /*portion*/, float /*seconds*/) { }
diff --git a/ui.h b/ui.h
index ca72911..82d95a3 100644
--- a/ui.h
+++ b/ui.h
@@ -39,6 +39,7 @@
     // Set the overall recovery state ("background image").
     enum Icon { NONE, INSTALLING_UPDATE, ERASING, NO_COMMAND, ERROR };
     virtual void SetBackground(Icon icon) = 0;
+    virtual void SetSystemUpdateText(bool security_update) = 0;
 
     // --- progress indicator ---
     enum ProgressType { EMPTY, INDETERMINATE, DETERMINATE };