diff --git a/Makefile b/Makefile
index c656876..606b2f7 100644
--- a/Makefile
+++ b/Makefile
@@ -38,6 +38,8 @@
 croupier.flx: packages
 	pub run sky_tools -v build --manifest manifest.yaml --output-file $@
 
+# TODO(alexfandrianto): Switch from --args-for to --checked once
+# sky_tools v 16 is released. (https://github.com/flutter/tools/issues/53)
 .PHONY: start
 start: croupier.flx env-check packages
 	pub run sky_tools -v --very-verbose run_mojo \
@@ -45,7 +47,8 @@
 	--app $< $(MOJO_ANDROID_FLAGS) \
 	-- \
 	--enable-multiprocess \
-	--map-origin=https://mojo.v.io/=$(ETHER_BUILD_DIR)
+	--map-origin=https://mojo.v.io/=$(ETHER_BUILD_DIR) \
+	--args-for="mojo:sky_viewer --enable-checked-mode"
 
 .PHONY: mock
 mock:
@@ -56,10 +59,6 @@
 unmock:
 	mv lib/src/syncbase/log_writer.dart.backup lib/src/syncbase/log_writer.dart
 
-.PHONY: install
-install: packages
-	./packages/sky/sky_tool start --install --checked
-
 .PHONY: env-check
 env-check:
 ifndef MOJO_DIR
diff --git a/lib/components/game.dart b/lib/components/game.dart
index 7c70fe6..f360d4e 100644
--- a/lib/components/game.dart
+++ b/lib/components/game.dart
@@ -210,7 +210,6 @@
       try {
         HeartsGame game = config.game as HeartsGame;
         game.passCards(_combinePassing());
-        _clearPassing();
       } catch (e) {
         print("You can't do that! ${e.toString()}");
         config.game.debugString = e.toString();
@@ -221,6 +220,11 @@
   void _makeGameTakeCallback() {
     setState(() {
       try {
+        // TODO(alexfandrianto): Another way to clear these passing cards is to
+        // do so upon the transition from the pass phase to the take phase.
+        // However, since they are never seen outside of the Pass phase, it is
+        // also valid to clear them upon taking any cards.
+        _clearPassing();
         HeartsGame game = config.game as HeartsGame;
         game.takeCards();
       } catch (e) {