diff --git a/api/controller/sysroot.py b/api/controller/sysroot.py
index dcccaa0..dd37b3f 100644
--- a/api/controller/sysroot.py
+++ b/api/controller/sysroot.py
@@ -21,7 +21,8 @@
 
 
 @validate.require('build_target.name')
-def Create(input_proto, output_proto):
+@validate.validation_complete
+def Create(input_proto, output_proto, _config):
   """Create or replace a sysroot."""
   update_chroot = not input_proto.flags.chroot_current
   replace_sysroot = input_proto.flags.replace
@@ -45,7 +46,9 @@
 
 
 @validate.require('sysroot.path', 'sysroot.build_target.name')
-def InstallToolchain(input_proto, output_proto):
+@validate.exists('sysroot.path')
+@validate.validation_complete
+def InstallToolchain(input_proto, output_proto, _config):
   """Install the toolchain into a sysroot."""
   compile_source = input_proto.flags.compile_source
 
@@ -56,9 +59,6 @@
   target_sysroot = sysroot_lib.Sysroot(sysroot_path)
   run_configs = sysroot.SetupBoardRunConfig(usepkg=not compile_source)
 
-  if not target_sysroot.Exists():
-    cros_build_lib.Die('Sysroot has not been created. Run Create first.')
-
   _LogBinhost(build_target.name)
 
   try:
@@ -73,7 +73,8 @@
 
 
 @validate.require('sysroot.path', 'sysroot.build_target.name')
-def InstallPackages(input_proto, output_proto):
+@validate.validation_complete
+def InstallPackages(input_proto, output_proto, _config):
   """Install packages into a sysroot, building as necessary and permitted."""
   compile_source = input_proto.flags.compile_source
   event_file = input_proto.flags.event_file