1 files changed, 1 insertions, 0 deletions
diff --git a/bignum.c b/bignum.c
index e49a18b118..e6ecb3933b 100644
--- a/bignum.c
+++ b/bignum.c
@@ -104,6 +104,7 @@ bigtrunc(x)
     long len = RBIGNUM(x)->len;
     BDIGIT *ds = BDIGITS(x);
 
+    if (len == 0) return x;
     while (--len && !ds[len]);
     RBIGNUM(x)->len = ++len;
     return x;