diff --git a/bignum.c b/bignum.c
index 5711dd8df11aae..17fab7bf856363 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;
-    long t2;
+    unsigned long t2;
     long num;
     USHORT dd, q;