diff --git a/include/tpm-v1.h b/include/tpm-v1.h
index 45b7a48..59ad4ae 100644
--- a/include/tpm-v1.h
+++ b/include/tpm-v1.h
@@ -8,6 +8,7 @@
 #define __TPM_V1_H
 
 #include <tpm-common.h>
+#include <linux/bitops.h>
 
 /* Useful constants */
 enum {