diff --git a/mboxd_msg.c b/mboxd_msg.c
index d02e0bf..0cc1cd2 100644
--- a/mboxd_msg.c
+++ b/mboxd_msg.c
@@ -147,6 +147,20 @@
 }
 
 /*
+ * get_suggested_timeout() - get the suggested timeout value in seconds
+ * @context:	The mbox context pointer
+ *
+ * Return:	Suggested timeout in seconds
+ */
+static uint16_t get_suggested_timeout(struct mbox_context *context)
+{
+	struct window_context *window = find_largest_window(context);
+	uint32_t max_size_mb = window ? (window->size >> 20) : 0;
+
+	return align_up(max_size_mb * FLASH_ACCESS_MS_PER_MB, 1000) / 1000;
+}
+
+/*
  * Command: GET_MBOX_INFO
  * Get the API version, default window size and block size
  * We also set the LPC mapping to point to the reserved memory region here so
@@ -229,6 +243,7 @@
 	}
 	if (context->version >= API_VERSION_2) {
 		resp->args[5] = context->block_size_shift;
+		put_u16(&resp->args[6], get_suggested_timeout(context));
 	}
 
 	return 0;
diff --git a/mboxd_msg.h b/mboxd_msg.h
index 44a2f91..7d81d7a 100644
--- a/mboxd_msg.h
+++ b/mboxd_msg.h
@@ -18,8 +18,13 @@
 #ifndef MBOXD_MSG_H
 #define MBOXD_MSG_H
 
-#define NO_BMC_EVENT	false
-#define SET_BMC_EVENT	true
+#include "common.h"
+
+/* Estimate as to how long (milliseconds) it takes to access a MB from flash */
+#define FLASH_ACCESS_MS_PER_MB		8000
+
+#define NO_BMC_EVENT			false
+#define SET_BMC_EVENT			true
 
 struct mbox_msg {
 	uint8_t command;
diff --git a/mboxd_windows.c b/mboxd_windows.c
index c64d19b..f02b0d7 100644
--- a/mboxd_windows.c
+++ b/mboxd_windows.c
@@ -479,6 +479,30 @@
 }
 
 /*
+ * find_largest_window() - Find the largest window in the window cache
+ * @context:	The mbox context pointer
+ *
+ * Return:	The largest window
+ */
+struct window_context *find_largest_window(struct mbox_context *context)
+{
+	struct window_context *largest = NULL, *cur;
+	uint32_t max_size = 0;
+	int i;
+
+	for (i = 0; i < context->windows.num; i++) {
+		cur = &context->windows.window[i];
+
+		if (cur->size > max_size) {
+			max_size = cur->size;
+			largest = cur;
+		}
+	}
+
+	return largest;
+}
+
+/*
  * search_windows() - Search the window cache for a window containing offset
  * @context:	The mbox context pointer
  * @offset:	Absolute flash offset to search for (bytes)
diff --git a/mboxd_windows.h b/mboxd_windows.h
index 3625521..925697c 100644
--- a/mboxd_windows.h
+++ b/mboxd_windows.h
@@ -40,6 +40,7 @@
 void reset_window(struct mbox_context *context, struct window_context *window);
 void reset_all_windows(struct mbox_context *context, bool set_bmc_event);
 struct window_context *find_oldest_window(struct mbox_context *context);
+struct window_context *find_largest_window(struct mbox_context *context);
 struct window_context *search_windows(struct mbox_context *context,
 				      uint32_t offset, bool exact);
 int create_map_window(struct mbox_context *context,