1 files changed, 4 insertions, 0 deletions
diff --git a/time.c b/time.c
index d5215edde1..5ad1035c4d 100644
--- a/time.c
+++ b/time.c
@@ -2350,6 +2350,10 @@ time_timespec(VALUE num, int interval)
 	    d = modf(RFLOAT_VALUE(num), &f);
 	    if (d >= 0) {
 		t.tv_nsec = (int)(d*1e9+0.5);
+		if (t.tv_nsec >= 1000000000) {
+		    t.tv_nsec -= 1000000000;
+		    f += 1;
+		}
 	    }
 	    else if ((t.tv_nsec = (int)(-d*1e9+0.5)) > 0) {
 		t.tv_nsec = 1000000000 - t.tv_nsec;