1 files changed, 2 insertions, 1 deletions
diff --git a/ztdiag.c b/ztdiag.c
index a1e476c..e2be5f3 100755
--- a/ztdiag.c
+++ b/ztdiag.c
@@ -1,3 +1,4 @@
+#include <fcntl.h>
 #include <sys/ioctl.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -17,7 +18,7 @@ int main(int argc, char *argv[])
 		fprintf(stderr, "Usage: ztdiag <channel>\n");
 		exit(1);
 	}
-	fd = open("/dev/zap/ctl");
+	fd = open("/dev/zap/ctl", O_RDWR);
 	if (fd < 0) {
 		perror("open(/dev/zap/ctl");
 		exit(1);