diff --git a/include/dpusm/provider_api.h b/include/dpusm/provider_api.h
index 57a6d09..792b03c 100644
--- a/include/dpusm/provider_api.h
+++ b/include/dpusm/provider_api.h
@@ -165,8 +165,8 @@ typedef struct dpusm_provider_functions {
         void *(*open)(const char *path, int flags, int mode);
         /* returns E errors */
         int (*write)(void *fp_handle, void *data, size_t size,
-            size_t trailing_zeros, loff_t offset, ssize_t *resid,
-            int *err);
+            size_t trailing_zeros, loff_t offset, uint8_t ashift,
+            ssize_t *resid, int *err);
         void (*close)(void *fp_handle);
     } file;
 
diff --git a/include/dpusm/user_api.h b/include/dpusm/user_api.h
index 8261d9a..7121a09 100644
--- a/include/dpusm/user_api.h
+++ b/include/dpusm/user_api.h
@@ -165,7 +165,8 @@ typedef struct dpusm_user_functions {
         void *(*open)(void *provider, const char *path, int flags, int mode);
         /* returns E errors */
         int (*write)(void *fp_handle, void *data, size_t size,
-             size_t trailing_zeros, loff_t offset, ssize_t *resid, int *err);
+             size_t trailing_zeros, loff_t offset, uint8_t ashift,
+             ssize_t *resid, int *err);
         int (*close)(void *fp_handle);
     } file;
 
diff --git a/src/user.c b/src/user.c
index 453ae40..4452a1c 100644
--- a/src/user.c
+++ b/src/user.c
@@ -569,7 +569,8 @@ dpusm_file_open(void *provider, const char *path, int flags, int mode) {
 
 static int
 dpusm_file_write(void *fp_handle, void *data, size_t count,
-    size_t trailing_zeros, loff_t offset, ssize_t *resid, int *err) {
+    size_t trailing_zeros, loff_t offset, uint8_t ashift,
+    ssize_t *resid, int *err) {
     SAME_PROVIDERS(fp_handle, fp_dpusmh, data, dpusmh, EIO);
 
     /* file operations are optional */
@@ -578,7 +579,7 @@ dpusm_file_write(void *fp_handle, void *data, size_t count,
     }
 
     return FUNCS(fp_dpusmh->provider)->file.write(fp_dpusmh->handle,
-        dpusmh->handle, count, trailing_zeros, offset, resid, err);
+        dpusmh->handle, count, trailing_zeros, offset, ashift, resid, err);
 }
 
 static int