diff --git a/trusted_os/handler.go b/trusted_os/handler.go
index 5ec2669..871fbb2 100644
--- a/trusted_os/handler.go
+++ b/trusted_os/handler.go
@@ -17,6 +17,7 @@ package main
 import (
 	"log"
 
+	"github.com/coreos/go-semver/semver"
 	"github.com/usbarmory/tamago/arm"
 	"github.com/usbarmory/tamago/bits"
 	"github.com/usbarmory/tamago/soc/nxp/imx6ul"
@@ -38,6 +39,25 @@ var irqHandler = make(map[int]func())
 func wakeHandler(g uint32, p uint32)
 func wakeHandlerPreGo123(g uint32, p uint32)
 
+// handlerCutover is the semver representation of the cut over between wakeHandler implementations above.
+// Anything less that this should use the legacy PreGo123 version.
+const handlerCutover = "1.23.0"
+
+var (
+	// wHandler is the wakeHandler implementation to be used, 1.23+ by default.
+	wHandler        = wakeHandler
+	wHandlerCutover = *semver.New(handlerCutover)
+)
+
+func configureWakeHandler(rtVersion semver.Version) {
+	if rtVersion.LessThan(wHandlerCutover) {
+		wHandler = wakeHandlerPreGo123
+		log.Printf("SM Using legacy pre-%s wakeHandler", wHandlerCutover.String())
+	} else {
+		wHandler = wakeHandler
+	}
+}
+
 func isr() {
 	irq := imx6ul.GIC.GetInterrupt(true)
 
@@ -45,7 +65,7 @@ func isr() {
 		handle()
 		return
 	}
-	log.Printf("unexpected IRQ %d", irq)
+	log.Printf("SM unexpected IRQ %d", irq)
 }
 
 func fiqHandler(ctx *monitor.ExecCtx) (_ error) {
@@ -67,7 +87,7 @@ func fiqHandler(ctx *monitor.ExecCtx) (_ error) {
 	// mask FIQs, applet handler will request unmasking when done
 	bits.Set(&ctx.SPSR, CPSR_FIQ)
 
-	wakeHandler(appletHandlerG, appletHandlerP)
+	wHandler(appletHandlerG, appletHandlerP)
 
 	return
 }
diff --git a/trusted_os/main.go b/trusted_os/main.go
index ec59d4e..29f60b1 100644
--- a/trusted_os/main.go
+++ b/trusted_os/main.go
@@ -228,7 +228,10 @@ func main() {
 					log.Printf("SM applet verification error, %v", err)
 				}
 				loadedAppletVersion = manifest.Git.TagName
-				log.Printf("SM Loaded applet version %s", loadedAppletVersion.String())
+				loadedAppletRuntime := manifest.Build.TamagoVersion
+				log.Printf("SM Loaded applet version %s (with TamaGo runtime %s)", loadedAppletVersion.String(), loadedAppletRuntime.String())
+
+				configureWakeHandler(loadedAppletRuntime)
 
 				usbarmory.LED("white", true)