diff --git a/src/dawn_native/Instance.cpp b/src/dawn_native/Instance.cpp
index 2f7566c..6786f7f 100644
--- a/src/dawn_native/Instance.cpp
+++ b/src/dawn_native/Instance.cpp
@@ -54,6 +54,10 @@
     void InstanceBase::DiscoverDefaultAdapters() {
         EnsureBackendConnections();
 
+        if (mDiscoveredDefaultAdapters) {
+            return;
+        }
+
         // Query and merge all default adapters for all backends
         for (std::unique_ptr<BackendConnection>& backend : mBackends) {
             std::vector<std::unique_ptr<AdapterBase>> backendAdapters =
@@ -65,6 +69,8 @@
                 mAdapters.push_back(std::move(adapter));
             }
         }
+
+        mDiscoveredDefaultAdapters = true;
     }
 
     // This is just a wrapper around the real logic that uses Error.h error handling.
diff --git a/src/dawn_native/Instance.h b/src/dawn_native/Instance.h
index 835d51d..895f710 100644
--- a/src/dawn_native/Instance.h
+++ b/src/dawn_native/Instance.h
@@ -50,6 +50,7 @@
         MaybeError DiscoverAdaptersInternal(const AdapterDiscoveryOptionsBase* options);
 
         bool mBackendsConnected = false;
+        bool mDiscoveredDefaultAdapters = false;
 
         std::vector<std::unique_ptr<BackendConnection>> mBackends;
         std::vector<std::unique_ptr<AdapterBase>> mAdapters;