diff --git a/src/armnn/DeviceSpec.hpp b/src/armnn/DeviceSpec.hpp
index 703a4b1..a1457cf 100644
--- a/src/armnn/DeviceSpec.hpp
+++ b/src/armnn/DeviceSpec.hpp
@@ -14,6 +14,9 @@
 class DeviceSpec : public IDeviceSpec
 {
 public:
+    DeviceSpec()
+    {}
+
     DeviceSpec(const BackendIdSet& supportedBackends)
         : m_SupportedBackends{supportedBackends} {}
 
@@ -48,7 +51,6 @@
     }
 
 private:
-    DeviceSpec() = delete;
     BackendIdSet m_SupportedBackends;
     BackendIdSet m_DynamicBackends;
 };
diff --git a/src/armnn/Runtime.cpp b/src/armnn/Runtime.cpp
index 2d7269a..47c998a 100644
--- a/src/armnn/Runtime.cpp
+++ b/src/armnn/Runtime.cpp
@@ -153,7 +153,6 @@
 
 Runtime::Runtime(const CreationOptions& options)
     : m_NetworkIdCounter(0)
-    , m_DeviceSpec{BackendRegistryInstance().GetBackendIds()}
 {
     ARMNN_LOG(info) << "ArmNN v" << ARMNN_VERSION << "\n";
 
@@ -164,12 +163,11 @@
     // goes through the backend registry
     LoadDynamicBackends(options.m_DynamicBackendsPath);
 
+    BackendIdSet supportedBackends;
     for (const auto& id : BackendRegistryInstance().GetBackendIds())
     {
         // Store backend contexts for the supported ones
-        const BackendIdSet& supportedBackends = m_DeviceSpec.GetSupportedBackends();
-        if (supportedBackends.find(id) != supportedBackends.end())
-        {
+        try {
             auto factoryFun = BackendRegistryInstance().GetFactory(id);
             auto backend = factoryFun();
             BOOST_ASSERT(backend.get() != nullptr);
@@ -182,8 +180,15 @@
             {
                 m_BackendContexts.emplace(std::make_pair(id, std::move(context)));
             }
+            supportedBackends.emplace(id);
         }
+        catch (const BackendUnavailableException&)
+        {
+            // Ignore backends which are unavailable
+        }
+
     }
+    m_DeviceSpec.AddSupportedBackends(supportedBackends);
 }
 
 Runtime::~Runtime()
diff --git a/src/armnn/Runtime.hpp b/src/armnn/Runtime.hpp
index e5debbf..2ad3c96 100644
--- a/src/armnn/Runtime.hpp
+++ b/src/armnn/Runtime.hpp
@@ -73,8 +73,6 @@
     virtual void RegisterDebugCallback(NetworkId networkId, const DebugCallbackFunction& func) override;
 
     /// Creates a runtime for workload execution.
-    /// May throw a ClRuntimeUnavailableException if @a defaultComputeDevice requires a CL runtime but
-    /// it cannot be setup for some reason.
     Runtime(const CreationOptions& options);
 
     ~Runtime();