diff --git a/include/nickel/argparse.h b/include/nickel/argparse.h
index e69de29..da1b842 100644
--- a/include/nickel/argparse.h
+++ b/include/nickel/argparse.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_ARGPARSE_H_
+#define __NICKEL_ARGPARSE_H_
+
+#endif  /* __NICKEL_ARGPARSE_H_ */
\ No newline at end of file
diff --git a/include/nickel/bitman.h b/include/nickel/bitman.h
new file mode 100644
index 0000000..ca35a63
--- /dev/null
+++ b/include/nickel/bitman.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_BITMAN_H_
+#define __NICKEL_BITMAN_H_
+
+#endif  /* __NICKEL_BITMAN_H_ */
\ No newline at end of file
diff --git a/include/nickel/bitset.h b/include/nickel/bitset.h
deleted file mode 100644
index e69de29..0000000
diff --git a/include/nickel/buf.h b/include/nickel/buf.h
index e69de29..689d71b 100644
--- a/include/nickel/buf.h
+++ b/include/nickel/buf.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_BUF_H_
+#define __NICKEL_BUF_H_
+
+#endif  /* __NICKEL_BUF_H_ */
\ No newline at end of file
diff --git a/include/nickel/ctassert.h b/include/nickel/ctassert.h
index e69de29..bc82574 100644
--- a/include/nickel/ctassert.h
+++ b/include/nickel/ctassert.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_CTASSERT_H_
+#define __NICKEL_CTASSERT_H_
+
+#endif  /* __NICKEL_CTASSERT_H_ */
\ No newline at end of file
diff --git a/include/nickel/defer.h b/include/nickel/defer.h
index e69de29..13d7afe 100644
--- a/include/nickel/defer.h
+++ b/include/nickel/defer.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_DEFER_H_
+#define __NICKEL_DEFER_H_
+
+#endif  /* __NICKEL_DEFER_H_ */
\ No newline at end of file
diff --git a/include/nickel/hashmap.h b/include/nickel/hashmap.h
index e69de29..f63bb37 100644
--- a/include/nickel/hashmap.h
+++ b/include/nickel/hashmap.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_HASHMAP_H_
+#define __NICKEL_HASHMAP_H_
+
+#endif  /* __NICKEL_HASHMAP_H_ */
\ No newline at end of file
diff --git a/include/nickel/ini.h b/include/nickel/ini.h
index e69de29..bb4d47f 100644
--- a/include/nickel/ini.h
+++ b/include/nickel/ini.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_INI_H_
+#define __NICKEL_INI_H_
+
+#endif  /* __NICKEL_INI_H_ */
\ No newline at end of file
diff --git a/include/nickel/io.h b/include/nickel/io.h
index e69de29..c60f0f2 100644
--- a/include/nickel/io.h
+++ b/include/nickel/io.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_IO_H_
+#define __NICKEL_IO_H_
+
+#endif  /* __NICKEL_IO_H_ */
\ No newline at end of file
diff --git a/include/nickel/log.h b/include/nickel/log.h
index e69de29..70e4d90 100644
--- a/include/nickel/log.h
+++ b/include/nickel/log.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_LOG_H_
+#define __NICKEL_LOG_H_
+
+#endif  /* __NICKEL_LOG_H_ */
\ No newline at end of file
diff --git a/include/nickel/refcnt.h b/include/nickel/refcnt.h
index e69de29..ac1f7aa 100644
--- a/include/nickel/refcnt.h
+++ b/include/nickel/refcnt.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_REFCNT_H_
+#define __NICKEL_REFCNT_H_
+
+#endif  /* __NICKEL_REFCNT_H_ */
\ No newline at end of file
diff --git a/include/nickel/result.h b/include/nickel/result.h
index e69de29..cdeb3bf 100644
--- a/include/nickel/result.h
+++ b/include/nickel/result.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_RESULT_H_
+#define __NICKEL_RESULT_H_
+
+#endif  /* __NICKEL_RESULT_H_ */
\ No newline at end of file
diff --git a/include/nickel/ring_spsc.h b/include/nickel/ring_spsc.h
index e69de29..29ae2be 100644
--- a/include/nickel/ring_spsc.h
+++ b/include/nickel/ring_spsc.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_RINGSPSC_H_
+#define __NICKEL_RINGSPSC_H_
+
+#endif  /* __NICKEL_RINGSPSC_H_ */
\ No newline at end of file
diff --git a/include/nickel/span.h b/include/nickel/span.h
index e69de29..2cfe260 100644
--- a/include/nickel/span.h
+++ b/include/nickel/span.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_SPAN_H_
+#define __NICKEL_SPAN_H_
+
+#endif  /* __NICKEL_SPAN_H_ */
\ No newline at end of file
diff --git a/include/nickel/threadpool.h b/include/nickel/threadpool.h
index e69de29..0f06980 100644
--- a/include/nickel/threadpool.h
+++ b/include/nickel/threadpool.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_THREADPOOL_H_
+#define __NICKEL_THREADPOOL_H_
+
+#endif  /* __NICKEL_THREADPOOL_H_ */
\ No newline at end of file
diff --git a/include/nickel/timeutil.h b/include/nickel/timeutil.h
index e69de29..8680f09 100644
--- a/include/nickel/timeutil.h
+++ b/include/nickel/timeutil.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_TIMEUTIL_H_
+#define __NICKEL_TIMEUTIL_H_
+
+#endif  /* __NICKEL_TIMEUTIL_H_ */
\ No newline at end of file
diff --git a/include/nickel/version.h b/include/nickel/version.h
index e69de29..6b33a6e 100644
--- a/include/nickel/version.h
+++ b/include/nickel/version.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_VERSION_H_
+#define __NICKEL_VERSION_H_
+
+#endif  /* __NICKEL_VERSION_H_ */
\ No newline at end of file
diff --git a/include/nickel/xalloc.h b/include/nickel/xalloc.h
index e69de29..f7ffbe2 100644
--- a/include/nickel/xalloc.h
+++ b/include/nickel/xalloc.h
@@ -0,0 +1,4 @@
+#ifndef __NICKEL_XALLOC_H_
+#define __NICKEL_XALLOC_H_
+
+#endif  /* __NICKEL_XALLOC_H_ */
\ No newline at end of file