1 files changed, 5 insertions, 2 deletions
diff --git a/bignum.c b/bignum.c
index fb0dafb142..5711dd8df1 100644
--- a/bignum.c
+++ b/bignum.c
@@ -721,7 +721,7 @@ bigdivmod(x, y, div, mod, modulo)
     long i, j;
     VALUE yy, z;
     USHORT *xds, *yds, *zds, *tds;
-    unsigned long t2;
+    long t2;
     long num;
     USHORT dd, q;
 
@@ -746,7 +746,10 @@ bigdivmod(x, y, div, mod, modulo)
 	RBIGNUM(z)->sign = RBIGNUM(x)->sign==RBIGNUM(y)->sign;
 	if (div) *div = bignorm(z);
 	if (mod) {
-	    if (!RBIGNUM(y)->sign) t2 = -(long)t2;
+	    if (!RBIGNUM(x)->sign) t2 = -(long)t2;
+	    if (modulo && RBIGNUM(x)->sign != RBIGNUM(y)->sign) {
+		t2 = t2 + yds[0] * (RBIGNUM(y)->sign ? 1 : -1);
+	    }
 	    *mod = INT2NUM(t2);
 	}
 	return;