diff --git a/app/Makefile b/app/Makefile
index 3a421de..523ac0b 100644
--- a/app/Makefile
+++ b/app/Makefile
@@ -69,7 +69,7 @@ include Makefile.app-config
 	./.Makefile.scripts/make--AndroidManifest.xml
 
 # !!this step (when/if) run will trigger a restart of the "make" as the rules tartget is included
-Makefile.app-config: app-config.sh Makefile
+Makefile.app-config: app-config.sh Makefile ./android-sdk/installed
 	source app-config.sh; \
 	tee $@ << MAKEFILE_APP_CONFIG
 	BUILDTOOLS:=$${ANDROID_SDK_ROOT}/$$(tr ';' '/' < android-sdk/.installed.buildtools.version.current)