1 files changed, 2 insertions, 0 deletions

diff --git a/inflate.c b/inflate.c
index 82e39be..2889e3a 100644
--- a/inflate.c
+++ b/inflate.c
@@ -645,6 +645,8 @@ int flush;
             NEEDBITS(16);
 #ifdef GUNZIP
             if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
+                if (state->wbits == 0)
+                    state->wbits = 15;
                 state->check = crc32(0L, Z_NULL, 0);
                 CRC2(state->check, hold);
                 INITBITS();