diff --git a/firmware/2lib/2ui_screens.c b/firmware/2lib/2ui_screens.c
index 878b4ed..2ec779c 100644
--- a/firmware/2lib/2ui_screens.c
+++ b/firmware/2lib/2ui_screens.c
@@ -1129,7 +1129,12 @@
 		return VB2_REQUEST_UI_CONTINUE;
 
 	vb2_error_t rv = op(reset, &log_string);
-	if ((rv && rv != VB2_ERROR_EX_DIAG_TEST_RUNNING) || !log_string) {
+
+	/* The test is still running but the output buffer was unchanged. */
+	if (rv == VB2_ERROR_EX_DIAG_TEST_RUNNING)
+		return VB2_REQUEST_UI_CONTINUE;
+
+	if ((rv && rv != VB2_ERROR_EX_DIAG_TEST_UPDATED) || !log_string) {
 		VB2_DEBUG("ERROR: Failed to retrieve memory test status\n");
 		ui->error_code = VB2_UI_ERROR_DIAGNOSTICS;
 		return vb2_ui_screen_back(ui);
@@ -1152,7 +1157,7 @@
 	VB2_CLR_BIT(ui->state->hidden_item_mask,
 		    DIAGNOSTICS_MEMORY_ITEM_CANCEL);
 	VB2_CLR_BIT(ui->state->hidden_item_mask, DIAGNOSTICS_MEMORY_ITEM_BACK);
-	if (rv == VB2_ERROR_EX_DIAG_TEST_RUNNING) {
+	if (rv == VB2_ERROR_EX_DIAG_TEST_UPDATED) {
 		VB2_SET_BIT(ui->state->hidden_item_mask,
 			    DIAGNOSTICS_MEMORY_ITEM_BACK);
 		if (ui->state->selected_item == DIAGNOSTICS_MEMORY_ITEM_BACK)
diff --git a/firmware/2lib/include/2api.h b/firmware/2lib/include/2api.h
index b4dfadf..4c5e1dc 100644
--- a/firmware/2lib/include/2api.h
+++ b/firmware/2lib/include/2api.h
@@ -1513,7 +1513,7 @@
  * control for a short period of time running memory test, and then return the
  * result of current status. If `reset` is not zero, it will reset the memory
  * test state.
- * *
+ *
  * @param reset	Discard the current memory test result and re-initialize
  *		a new test.
  * @param out	For returning a read-only pointer of full log string which is
@@ -1522,7 +1522,9 @@
  *		until next call.
  * @return The status of memory test. VB2_SUCCESS means the test is finished,
  * regardless of passing or failing. VB2_ERROR_EX_DIAG_TEST_RUNNING means
- * the test is still running. Other non-zero codes for internal errors.
+ * the test is still running but the output buffer was unchanged.
+ * VB2_ERROR_EX_DIAG_TEST_UPDATED means the test is still running and the output
+ * buffer was updated. Other non-zero codes for internal errors.
  */
 vb2_error_t vb2ex_diag_memory_quick_test(int reset, const char **out);
 vb2_error_t vb2ex_diag_memory_full_test(int reset, const char **out);
diff --git a/firmware/2lib/include/2return_codes.h b/firmware/2lib/include/2return_codes.h
index 3a50f94..4abe16a 100644
--- a/firmware/2lib/include/2return_codes.h
+++ b/firmware/2lib/include/2return_codes.h
@@ -731,9 +731,12 @@
 	/* Error setting vendor data (see: VbExSetVendorData). */
 	VB2_ERROR_EX_SET_VENDOR_DATA,
 
-	/* The memory test is running. */
+	/* The memory test is running but the output buffer was unchanged. */
 	VB2_ERROR_EX_DIAG_TEST_RUNNING,
 
+	/* The memory test is running and the output buffer was updated. */
+	VB2_ERROR_EX_DIAG_TEST_UPDATED,
+
 	/* The memory test initialization failed. */
 	VB2_ERROR_EX_DIAG_TEST_INIT_FAILED,