diff --git a/driver_library/include/ethosu.hpp b/driver_library/include/ethosu.hpp
index da8dbbd..74f8abb 100644
--- a/driver_library/include/ethosu.hpp
+++ b/driver_library/include/ethosu.hpp
@@ -81,10 +81,10 @@
  */
 struct HardwareId {
 public:
-    HardwareId(uint32_t _versionStatus,
-               const SemanticVersion &_version,
-               const SemanticVersion &_product,
-               const SemanticVersion &_architecture) :
+    HardwareId(uint32_t _versionStatus              = 0,
+               const SemanticVersion &_version      = SemanticVersion(),
+               const SemanticVersion &_product      = SemanticVersion(),
+               const SemanticVersion &_architecture = SemanticVersion()) :
         versionStatus(_versionStatus),
         version(_version), product(_product), architecture(_architecture) {}
 
@@ -102,7 +102,7 @@
  */
 struct HardwareConfiguration {
 public:
-    HardwareConfiguration(uint32_t _macsPerClockCycle, uint32_t _cmdStreamVersion, bool _customDma) :
+    HardwareConfiguration(uint32_t _macsPerClockCycle = 0, uint32_t _cmdStreamVersion = 0, bool _customDma = false) :
         macsPerClockCycle(_macsPerClockCycle), cmdStreamVersion(_cmdStreamVersion), customDma(_customDma) {}
 
     uint32_t macsPerClockCycle;
@@ -118,6 +118,7 @@
  */
 class Capabilities {
 public:
+    Capabilities() {}
     Capabilities(const HardwareId &_hwId, const HardwareConfiguration &_hwCfg, const SemanticVersion &_driver) :
         hwId(_hwId), hwCfg(_hwCfg), driver(_driver) {}