diff --git a/hwc3/Composer.cpp b/hwc3/Composer.cpp
index 2494488..4977a14 100644
--- a/hwc3/Composer.cpp
+++ b/hwc3/Composer.cpp
@@ -32,6 +32,10 @@
     std::shared_ptr<IComposerClient>* out_client) {
   DEBUG_FUNC();
 
+  if (!client_.expired()) {
+    return ToBinderStatus(hwc3::Error::kNoResources);
+  }
+
   auto client = ndk::SharedRefBase::make<ComposerClient>();
   if (!client || !client->Init()) {
     *out_client = nullptr;
diff --git a/hwc3/ComposerClient.cpp b/hwc3/ComposerClient.cpp
index 6c03722..e49698f 100644
--- a/hwc3/ComposerClient.cpp
+++ b/hwc3/ComposerClient.cpp
@@ -25,6 +25,7 @@
 #include <hardware/hwcomposer2.h>
 
 #include <cinttypes>
+#include <cmath>
 #include <memory>
 #include <unordered_map>
 #include <vector>
@@ -881,6 +882,10 @@
     return ToBinderStatus(hwc3::Error::kBadDisplay);
   }
 
+  if (mode == PowerMode::ON_SUSPEND) {
+    return ToBinderStatus(hwc3::Error::kUnsupported);
+  }
+
   auto error = display->SetPowerMode(Hwc3PowerModeToHwc2(mode));
   return ToBinderStatus(Hwc2toHwc3Error(error));
 }