diff --git a/library/bignum.c b/library/bignum.c
index 0eb2125..af9a399 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -1607,10 +1607,10 @@
 
     t++;
 
-    do {
+    while( c != 0 )
+    {
         *d += c; c = ( *d < c ); d++;
     }
-    while( c != 0 );
 }
 
 /*