diff --git a/src/ruby/ext/grpc/rb_grpc.c b/src/ruby/ext/grpc/rb_grpc.c
index b0b37a8..1bb4020 100644
--- a/src/ruby/ext/grpc/rb_grpc.c
+++ b/src/ruby/ext/grpc/rb_grpc.c
@@ -139,7 +139,7 @@
           rb_raise(rb_eRangeError, "%f out of Time range",
                    RFLOAT_VALUE(time));
         }
-        t.tv_nsec = (int)(time_t)(d * 1e9 + 0.5);
+        t.tv_nsec = (int)(d * 1e9 + 0.5);
       }
       break;