diff --git a/libcli/smb/smb2cli_ioctl.c b/libcli/smb/smb2cli_ioctl.c
index 2881c742ce5..983646981a7 100644
--- a/libcli/smb/smb2cli_ioctl.c
+++ b/libcli/smb/smb2cli_ioctl.c
@@ -77,7 +77,7 @@ struct tevent_req *smb2cli_ioctl_send(TALLOC_CTX *mem_ctx,
 
 	if (in_output_buffer) {
 		output_buffer_offset = SMB2_HDR_BODY+0x38;
-		if (input_buffer_length > 0) {
+		if (input_buffer_length > 0 && output_buffer_length > 0) {
 			uint32_t tmp;
 			output_buffer_offset += input_buffer_length;
 			tmp = output_buffer_offset;