1 files changed, 1 insertions, 1 deletions

diff --git a/gzwrite.c b/gzwrite.c
index 427840d..e8defc6 100644
--- a/gzwrite.c
+++ b/gzwrite.c
@@ -318,7 +318,7 @@ int ZEXPORTVA gzprintf (gzFile file, const char *format, ...)
 #  ifdef HAS_vsprintf_void
     (void)vsprintf(state->in, format, va);
     va_end(va);
-    for (len = 0; len < state->in; len++)
+    for (len = 0; len < size; len++)
         if (state->in[len] == 0) break;
 #  else
     len = vsprintf(state->in, format, va);