1 files changed, 4 insertions, 2 deletions
diff --git a/sha1dc/sha1.h b/sha1dc/sha1.h
index 8855617..7d4d423 100644
--- a/sha1dc/sha1.h
+++ b/sha1dc/sha1.h
@@ -4,13 +4,13 @@
 * See accompanying file LICENSE.txt or copy at
 * https://opensource.org/licenses/MIT
 ***/
+#ifndef SHA1DC_SHA1_H
+#define SHA1DC_SHA1_H
 
 #if defined(__cplusplus)
 extern "C" {
 #endif
 
-#include <stdint.h>
-
 /* uses SHA-1 message expansion to expand the first 16 words of W[] to 80 words */
 /* void sha1_message_expansion(uint32_t W[80]); */
 
@@ -103,3 +103,5 @@ int  SHA1DCFinal(unsigned char[20], SHA1_CTX*);
 #if defined(__cplusplus)
 }
 #endif
+
+#endif /* SHA1DC_SHA1_H */