gap5/zfio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gap5/zfio.c b/gap5/zfio.c
index 35da12a..1b628e4 100644
--- a/gap5/zfio.c
+++ b/gap5/zfio.c
@@ -51,7 +51,7 @@ int zfpeek(zfp *zf) {
 	if (c != EOF)
 	    ungetc(c, zf->fp);
     } else {
-	c = gzgetc(zf->gz);
+	c = gzgetc((gzFile)zf->gz);
 	if (c != EOF)
 	    gzungetc(c, zf->gz);
     }