diff --git a/include/internal/catch_random_number_generator.h b/include/internal/catch_random_number_generator.h
index 1a61202d..2395bd39 100644
--- a/include/internal/catch_random_number_generator.h
+++ b/include/internal/catch_random_number_generator.h
@@ -20,7 +20,7 @@ namespace Catch {
     unsigned int rngSeed();
 
     struct RandomNumberGenerator {
-        using result_type = std::ptrdiff_t;
+        using result_type = unsigned int;
 
         static constexpr result_type (min)() { return 0; }
         static constexpr result_type (max)() { return 1000000; }