1 files changed, 1 insertions, 1 deletions
diff --git a/mpfr.c b/mpfr.c
index b15c9b0b..f2c58116 100644
--- a/mpfr.c
+++ b/mpfr.c
@@ -327,7 +327,7 @@ force_mpnum(NODE *n, int do_nondec, int use_locale)
 	IEEE_FMT(n->mpg_numbr, tval);
 done:
 	/* trailing space is OK for NUMBER */
-	while (isspace((unsigned char) *ptr))
+	while (ptr < cpend && isspace((unsigned char) *ptr))
 		ptr++;
 	*cpend = save;
 	if (errno == 0 && ptr == cpend)