diff --git a/driver_library/src/ethosu.cpp b/driver_library/src/ethosu.cpp
index 7aec696..a4feef1 100644
--- a/driver_library/src/ethosu.cpp
+++ b/driver_library/src/ethosu.cpp
@@ -539,9 +539,9 @@
     throw Exception("Unknown inference status");
 }
 
-const std::vector<uint32_t> Inference::getPmuCounters() const {
+const std::vector<uint64_t> Inference::getPmuCounters() const {
     ethosu_uapi_result_status uapi;
-    std::vector<uint32_t> counterValues = std::vector<uint32_t>(ETHOSU_PMU_EVENT_MAX, 0);
+    std::vector<uint64_t> counterValues = std::vector<uint64_t>(ETHOSU_PMU_EVENT_MAX, 0);
 
     eioctl(fd, ETHOSU_IOCTL_INFERENCE_STATUS, static_cast<void *>(&uapi));