diff --git a/include/tpax/tpax.h b/include/tpax/tpax.h
index ad596c4..89c3bfc 100644
--- a/include/tpax/tpax.h
+++ b/include/tpax/tpax.h
@@ -157,9 +157,9 @@ tpax_api int  tpax_archive_write            (const struct tpax_driver_ctx *);
 
 tpax_api int  tpax_archive_seal             (const struct tpax_driver_ctx *);
 
-/* helper api */
-tpax_api int  tpax_path_copy            (char *, const char *, size_t, uint32_t, size_t *);
-tpax_api int  tpax_stat_compare         (const struct stat *, const struct stat *);
+/* utility helper interfaces */
+tpax_api int  tpax_util_path_copy           (char *, const char *, size_t, uint32_t, size_t *);
+tpax_api int  tpax_util_stat_compare        (const struct stat *, const struct stat *);
 
 /* utility api */
 tpax_api int  tpax_main                 (char **, char **,
diff --git a/project/common.mk b/project/common.mk
index e569cbd..637c282 100644
--- a/project/common.mk
+++ b/project/common.mk
@@ -2,8 +2,6 @@ API_SRCS = \
 	src/driver/tpax_amain.c \
 	src/driver/tpax_driver_ctx.c \
 	src/driver/tpax_unit_ctx.c \
-	src/helper/tpax_path_copy.c \
-	src/helper/tpax_stat_compare.c \
 	src/logic/tpax_archive_append.c \
 	src/logic/tpax_archive_write.c \
 	src/logic/tpax_init_ustar_header.c \
@@ -12,6 +10,8 @@ API_SRCS = \
 	src/logic/tpax_queue_vector.c \
 	src/output/tpax_output_error.c \
 	src/skin/tpax_skin_default.c \
+	src/util/tpax_path_copy.c \
+	src/util/tpax_stat_compare.c \
 
 INTERNAL_SRCS = \
 	src/internal/$(PACKAGE)_dprintf_impl.c \
diff --git a/project/tree.mk b/project/tree.mk
index 548db6f..2f68c9e 100644
--- a/project/tree.mk
+++ b/project/tree.mk
@@ -1,10 +1,10 @@
 TREE_DIRS     = bin lib src \
 		src/driver \
-		src/helper \
 		src/internal \
 		src/logic \
 		src/output \
 		src/skin \
+		src/util \
 
 tree.tag:
 		mkdir -p $(TREE_DIRS)
diff --git a/src/helper/tpax_path_copy.c b/src/helper/tpax_path_copy.c
deleted file mode 100644
index 084cc73..0000000
--- a/src/helper/tpax_path_copy.c
+++ /dev/null
@@ -1,86 +0,0 @@
-/**************************************************************/
-/*  tpax: a topological pax implementation                    */
-/*  Copyright (C) 2020--2024  SysDeer Technologies, LLC       */
-/*  Released under GPLv2 and GPLv3; see COPYING.TPAX.         */
-/**************************************************************/
-
-#include <stdint.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <sys/stat.h>
-
-#include <tpax/tpax.h>
-#include "tpax_driver_impl.h"
-
-int tpax_path_copy(
-	char *          dstpath,
-	const char *    srcpath,
-	size_t          bufsize,
-	uint32_t        flags,
-	size_t *        nwritten)
-{
-	const char *    src;
-	char *          dst;
-	char *          cap;
-
-	if (!bufsize) {
-		errno = ENOBUFS;
-		return -1;
-	}
-
-	src = srcpath;
-	dst = dstpath;
-	cap = &dst[bufsize];
-
-	if ((src[0] == '/') && (src[1] == '/') && (src[2] != '/')) {
-		*dst++ = *src++;
-		*dst++ = *src++;
-	}
-
-	if (flags & TPAX_DRIVER_PURE_PATH_OUTPUT)
-		if ((src[0] == '.') && (src[1] == '/'))
-			for (++src; *src=='/'; src++)
-				(void)0;
-
-	for (; *src; ) {
-		if ((src[0] == '.') && (src[1] == '.')) {
-			if ((src[2] == '/') || (src[2] == '\0')) {
-				if (flags & TPAX_DRIVER_STRICT_PATH_INPUT) {
-					errno = EINVAL;
-					return -1;
-				}
-			}
-		}
-
-		if (flags & TPAX_DRIVER_PURE_PATH_OUTPUT) {
-			if ((src[0] == '.') && (src[1] == '/') && (src[-1] == '/')) {
-				for (++src; *src=='/'; src++)
-					(void)0;
-
-			} else if ((src[0] == '/')) {
-				for (src++; *src=='/'; src++)
-					(void)0;
-
-				*dst++ = '/';
-
-			} else {
-				*dst++ = *src++;
-			}
-		} else {
-			*dst++ = *src++;
-		}
-
-		if (dst == cap) {
-			errno = ENOBUFS;
-			return -1;
-		}
-	}
-
-	if (nwritten)
-		*nwritten = dst - dstpath;
-
-	*dst = '\0';
-
-	return 0;
-}
diff --git a/src/helper/tpax_stat_compare.c b/src/helper/tpax_stat_compare.c
deleted file mode 100644
index 398e45c..0000000
--- a/src/helper/tpax_stat_compare.c
+++ /dev/null
@@ -1,41 +0,0 @@
-/**************************************************************/
-/*  tpax: a topological pax implementation                    */
-/*  Copyright (C) 2020--2024  SysDeer Technologies, LLC       */
-/*  Released under GPLv2 and GPLv3; see COPYING.TPAX.         */
-/**************************************************************/
-
-#include <stdint.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <sys/stat.h>
-
-#include <tpax/tpax.h>
-#include "tpax_driver_impl.h"
-
-#define TPAX_STAT_COMPARE(member)                    \
-	if (src -> member - dst -> member)            \
-		return (src -> member > dst -> member) \
-			? (1) : (-1)
-
-int tpax_stat_compare(
-	const struct stat * src,
-	const struct stat * dst)
-{
-	TPAX_STAT_COMPARE(st_dev);
-	TPAX_STAT_COMPARE(st_ino);
-
-	TPAX_STAT_COMPARE(st_mode);
-	TPAX_STAT_COMPARE(st_uid);
-	TPAX_STAT_COMPARE(st_gid);
-
-	TPAX_STAT_COMPARE(st_rdev);
-	TPAX_STAT_COMPARE(st_size);
-	TPAX_STAT_COMPARE(st_blksize);
-	TPAX_STAT_COMPARE(st_blocks);
-
-	TPAX_STAT_COMPARE(st_mtim.tv_sec);
-	TPAX_STAT_COMPARE(st_mtim.tv_nsec);
-
-	return 0;
-}
diff --git a/src/logic/tpax_file_create_memory_snapshot.c b/src/logic/tpax_file_create_memory_snapshot.c
index 0cd0f0c..504a4a1 100644
--- a/src/logic/tpax_file_create_memory_snapshot.c
+++ b/src/logic/tpax_file_create_memory_snapshot.c
@@ -53,7 +53,7 @@ int tpax_file_create_memory_snapshot(
 		close(fd);
 		return TPAX_SYSTEM_ERROR(dctx);
 
-	} else if (tpax_stat_compare(srcst,&dstst)) {
+	} else if (tpax_util_stat_compare(srcst,&dstst)) {
 		close(fd);
 		return TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_FILE_CHANGED);
 	}
@@ -86,7 +86,7 @@ int tpax_file_create_memory_snapshot(
 		close(fd);
 		return TPAX_SYSTEM_ERROR(dctx);
 
-	} else if (tpax_stat_compare(srcst,&dstst)) {
+	} else if (tpax_util_stat_compare(srcst,&dstst)) {
 		close(fd);
 		return TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_FILE_CHANGED);
 	}
diff --git a/src/logic/tpax_file_create_tmpfs_snapshot.c b/src/logic/tpax_file_create_tmpfs_snapshot.c
index 5939ff4..2e92211 100644
--- a/src/logic/tpax_file_create_tmpfs_snapshot.c
+++ b/src/logic/tpax_file_create_tmpfs_snapshot.c
@@ -64,7 +64,7 @@ int tpax_file_create_tmpfs_snapshot(
 		close(fdtmp);
 		return TPAX_SYSTEM_ERROR(dctx);
 
-	} else if (tpax_stat_compare(srcst,&dstst)) {
+	} else if (tpax_util_stat_compare(srcst,&dstst)) {
 		close(fdsrc);
 		close(fdtmp);
 		return TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_FILE_CHANGED);
@@ -114,7 +114,7 @@ int tpax_file_create_tmpfs_snapshot(
 		close(fdtmp);
 		return TPAX_SYSTEM_ERROR(dctx);
 
-	} else if (tpax_stat_compare(srcst,&dstst)) {
+	} else if (tpax_util_stat_compare(srcst,&dstst)) {
 		close(fdsrc);
 		close(fdtmp);
 		return TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_FILE_CHANGED);
diff --git a/src/util/tpax_path_copy.c b/src/util/tpax_path_copy.c
new file mode 100644
index 0000000..046ddde
--- /dev/null
+++ b/src/util/tpax_path_copy.c
@@ -0,0 +1,86 @@
+/**************************************************************/
+/*  tpax: a topological pax implementation                    */
+/*  Copyright (C) 2020--2024  SysDeer Technologies, LLC       */
+/*  Released under GPLv2 and GPLv3; see COPYING.TPAX.         */
+/**************************************************************/
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/stat.h>
+
+#include <tpax/tpax.h>
+#include "tpax_driver_impl.h"
+
+int tpax_util_path_copy(
+	char *          dstpath,
+	const char *    srcpath,
+	size_t          bufsize,
+	uint32_t        flags,
+	size_t *        nwritten)
+{
+	const char *    src;
+	char *          dst;
+	char *          cap;
+
+	if (!bufsize) {
+		errno = ENOBUFS;
+		return -1;
+	}
+
+	src = srcpath;
+	dst = dstpath;
+	cap = &dst[bufsize];
+
+	if ((src[0] == '/') && (src[1] == '/') && (src[2] != '/')) {
+		*dst++ = *src++;
+		*dst++ = *src++;
+	}
+
+	if (flags & TPAX_DRIVER_PURE_PATH_OUTPUT)
+		if ((src[0] == '.') && (src[1] == '/'))
+			for (++src; *src=='/'; src++)
+				(void)0;
+
+	for (; *src; ) {
+		if ((src[0] == '.') && (src[1] == '.')) {
+			if ((src[2] == '/') || (src[2] == '\0')) {
+				if (flags & TPAX_DRIVER_STRICT_PATH_INPUT) {
+					errno = EINVAL;
+					return -1;
+				}
+			}
+		}
+
+		if (flags & TPAX_DRIVER_PURE_PATH_OUTPUT) {
+			if ((src[0] == '.') && (src[1] == '/') && (src[-1] == '/')) {
+				for (++src; *src=='/'; src++)
+					(void)0;
+
+			} else if ((src[0] == '/')) {
+				for (src++; *src=='/'; src++)
+					(void)0;
+
+				*dst++ = '/';
+
+			} else {
+				*dst++ = *src++;
+			}
+		} else {
+			*dst++ = *src++;
+		}
+
+		if (dst == cap) {
+			errno = ENOBUFS;
+			return -1;
+		}
+	}
+
+	if (nwritten)
+		*nwritten = dst - dstpath;
+
+	*dst = '\0';
+
+	return 0;
+}
diff --git a/src/util/tpax_stat_compare.c b/src/util/tpax_stat_compare.c
new file mode 100644
index 0000000..2de6922
--- /dev/null
+++ b/src/util/tpax_stat_compare.c
@@ -0,0 +1,41 @@
+/**************************************************************/
+/*  tpax: a topological pax implementation                    */
+/*  Copyright (C) 2020--2024  SysDeer Technologies, LLC       */
+/*  Released under GPLv2 and GPLv3; see COPYING.TPAX.         */
+/**************************************************************/
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/stat.h>
+
+#include <tpax/tpax.h>
+#include "tpax_driver_impl.h"
+
+#define TPAX_STAT_COMPARE(member)                    \
+	if (src -> member - dst -> member)            \
+		return (src -> member > dst -> member) \
+			? (1) : (-1)
+
+int tpax_util_stat_compare(
+	const struct stat * src,
+	const struct stat * dst)
+{
+	TPAX_STAT_COMPARE(st_dev);
+	TPAX_STAT_COMPARE(st_ino);
+
+	TPAX_STAT_COMPARE(st_mode);
+	TPAX_STAT_COMPARE(st_uid);
+	TPAX_STAT_COMPARE(st_gid);
+
+	TPAX_STAT_COMPARE(st_rdev);
+	TPAX_STAT_COMPARE(st_size);
+	TPAX_STAT_COMPARE(st_blksize);
+	TPAX_STAT_COMPARE(st_blocks);
+
+	TPAX_STAT_COMPARE(st_mtim.tv_sec);
+	TPAX_STAT_COMPARE(st_mtim.tv_nsec);
+
+	return 0;
+}