diff --git a/test/fully-connected-operator-tester.h b/test/fully-connected-operator-tester.h
index cfc3738..b1d4f76 100644
--- a/test/fully-connected-operator-tester.h
+++ b/test/fully-connected-operator-tester.h
@@ -15,6 +15,7 @@
 #include <algorithm>
 #include <cmath>
 #include <functional>
+#include <limits>
 #include <random>
 #include <vector>
 
@@ -132,7 +133,7 @@
     std::random_device random_device;
     auto rng = std::mt19937(random_device());
     auto s32rng = std::bind(std::uniform_int_distribution<int32_t>(-10000, 10000), rng);
-    auto u8rng = std::bind(std::uniform_int_distribution<uint8_t>(), rng);
+    auto u8rng = std::bind(std::uniform_int_distribution<uint32_t>(0, std::numeric_limits<uint8_t>::max()), rng);
 
     std::vector<uint8_t> input(XNN_EXTRA_BYTES / sizeof(uint8_t) +
       (batch_size() - 1) * input_stride() + input_channels());