diff --git a/src/driver/tpax_driver_ctx.c b/src/driver/tpax_driver_ctx.c
index 37ec718..7722ae4 100644
--- a/src/driver/tpax_driver_ctx.c
+++ b/src/driver/tpax_driver_ctx.c
@@ -304,6 +304,24 @@ static int tpax_driver_error_not_implemented(
 	return TPAX_FATAL;
 }
 
+static void tpax_set_archive_block_size(struct tpax_common_ctx * cctx)
+{
+	if (cctx->blksize)
+		(void)0;
+
+	else if (cctx->drvflags & TPAX_DRIVER_WRITE_FORMAT_PAX)
+		cctx->blksize = TPAX_PAX_BLOCK_SIZE;
+
+	else if (cctx->drvflags & TPAX_DRIVER_WRITE_FORMAT_CPIO)
+		cctx->blksize = TPAX_CPIO_BLOCK_SIZE;
+
+	else if (cctx->drvflags & TPAX_DRIVER_WRITE_FORMAT_USTAR)
+		cctx->blksize = TPAX_USTAR_BLOCK_SIZE;
+
+	else if (cctx->drvflags & TPAX_DRIVER_WRITE_FORMAT_RUSTAR)
+		cctx->blksize = TPAX_USTAR_BLOCK_SIZE;
+}
+
 static struct tpax_driver_ctx_impl * tpax_driver_ctx_alloc(
 	struct argv_meta *		meta,
 	const struct tpax_fd_ctx *	fdctx,
@@ -368,6 +386,8 @@ static struct tpax_driver_ctx_impl * tpax_driver_ctx_alloc(
 		}
 	}
 
+	tpax_set_archive_block_size(&ictx->ctx.cctx);
+
 	ictx->ctx.ctx.units = ictx->units;
 	ictx->ctx.ctx.errv  = ictx->ctx.errinfp;
 	return &ictx->ctx;
diff --git a/src/internal/tpax_driver_impl.h b/src/internal/tpax_driver_impl.h
index 1333f25..1345c32 100644
--- a/src/internal/tpax_driver_impl.h
+++ b/src/internal/tpax_driver_impl.h
@@ -260,24 +260,6 @@ static inline void tpax_set_unit_dpos(const struct tpax_unit_ctx * uctx, off_t d
 	ictx->dpos = dpos;
 }
 
-static inline ssize_t tpax_get_archive_block_size(const struct tpax_driver_ctx * dctx)
-{
-	if (dctx->cctx->drvflags & TPAX_DRIVER_WRITE_FORMAT_PAX)
-		return TPAX_PAX_BLOCK_SIZE;
-
-	else if (dctx->cctx->drvflags & TPAX_DRIVER_WRITE_FORMAT_CPIO)
-		return TPAX_CPIO_BLOCK_SIZE;
-
-	else if (dctx->cctx->drvflags & TPAX_DRIVER_WRITE_FORMAT_USTAR)
-		return TPAX_USTAR_BLOCK_SIZE;
-
-	else if (dctx->cctx->drvflags & TPAX_DRIVER_WRITE_FORMAT_RUSTAR)
-		return TPAX_USTAR_BLOCK_SIZE;
-
-	else
-		return 0;
-}
-
 int tpax_update_queue_vector(const struct tpax_driver_ctx * dctx);
 
 const char * tpax_queue_item_full_path(
diff --git a/src/logic/tpax_archive_write.c b/src/logic/tpax_archive_write.c
index 5214787..b0dad94 100644
--- a/src/logic/tpax_archive_write.c
+++ b/src/logic/tpax_archive_write.c
@@ -251,7 +251,7 @@ int tpax_archive_seal(const struct tpax_driver_ctx * dctx)
 	ssize_t blksize;
 	char    buf[512];
 
-	blksize = tpax_get_archive_block_size(dctx);
+	blksize = dctx->cctx->blksize;
 	cpos    = tpax_get_driver_cpos(dctx);
 
 	if (cpos % 512)