1 files changed, 1 insertions, 1 deletions
diff --git a/util.c b/util.c
index 05a442ba76..50ddb2b315 100644
--- a/util.c
+++ b/util.c
@@ -3362,7 +3362,7 @@ ruby_dtoa(double d_, int mode, int ndigits, int *decpt, int *sign, char **rve)
         if (i <= 0)
             i = 1;
     }
-    s = s0 = rv_alloc(i);
+    s = s0 = rv_alloc(i+1);
 
 #ifdef Honor_FLT_ROUNDS
     if (mode > 1 && rounding != 1)