diff --git a/bootloader/hos/secmon_exo.c b/bootloader/hos/secmon_exo.c
index 7b81e8a..9fb95cb 100644
--- a/bootloader/hos/secmon_exo.c
+++ b/bootloader/hos/secmon_exo.c
@@ -156,28 +156,24 @@ void config_exosphere(launch_ctxt_t *ctxt, u32 warmboot_base)
 
 	//! TODO: Replace current HOS version decoding (as it's bound to break in the future).
 
-	// Old exosphere target versioning. Use fuses for a simpler decoding.
-	if (ctxt->pkg1_id->fuses <= 3 || ctxt->pkg1_id->fuses >= 10) // 1.0.0 - 3.0.0, 8.1.0+.
+	// Old exosphere target versioning.
+	if (ctxt->pkg1_id->kb >= HOS_KB_VERSION_1210)                     // 12.1.0+
+		exo_fw_no = ctxt->pkg1_id->kb + 4;
+	else if (ctxt->pkg1_id->fuses <= 3 || ctxt->pkg1_id->fuses >= 10) // 1.0.0 - 3.0.0, 8.1.0 - 12.0.3.
 		exo_fw_no = ctxt->pkg1_id->fuses;
 	else
-		exo_fw_no = ctxt->pkg1_id->fuses - 1;                    // 3.0.1 - 7.0.1, 8.0.x.
+		exo_fw_no = ctxt->pkg1_id->fuses - 1;                         // 3.0.1 - 7.0.1, 8.0.x.
+
+	// Handle versions that change API and do not burn new fuse.
+	if (!memcmp(ctxt->pkg1_id->id, "20190314", 8) || //  8.0.x, same fuses with  7.0.1.
+		!memcmp(ctxt->pkg1_id->id, "20210129", 8)    // 12.0.0, same fuses with 11.0.0.
+	   )
+		exo_fw_no++;
 
 	// Set 12.1.0 specific revision.
 	if (ctxt->pkg1_id->kb == HOS_KB_VERSION_1210)
 		ctxt->exo_ctx.hos_revision = 1;
 
-	// Handle 15.0.0+.
-	if (ctxt->pkg1_id->fuses >= 17)
-		exo_fw_no++;
-
-	// Handle versions that change API and do not burn new fuse.
-	if (!memcmp(ctxt->pkg1_id->id, "20190314", 8) || //  8.0.x, same fuses with  7.0.1.
-		!memcmp(ctxt->pkg1_id->id, "20210129", 8) || // 12.0.0, same fuses with 11.0.0.
-		!memcmp(ctxt->pkg1_id->id, "20210805", 8) || // 13.0.0, same fuses with 12.1.0.
-		!memcmp(ctxt->pkg1_id->id, "20220209", 8)    // 14.0.0, same fuses with 13.2.1.
-	   )
-		exo_fw_no++;
-
 	// Feed old exosphere target versioning to new.
 	switch (exo_fw_no)
 	{