diff --git a/updater/blockimg.cpp b/updater/blockimg.cpp
index 6e05600..44de4e0 100644
--- a/updater/blockimg.cpp
+++ b/updater/blockimg.cpp
@@ -45,6 +45,7 @@
 #include "install.h"
 #include "openssl/sha.h"
 #include "minzip/Hash.h"
+#include "otafault/ota_io.h"
 #include "print_sha1.h"
 #include "unique_fd.h"
 #include "updater.h"
@@ -139,7 +140,7 @@
 static int read_all(int fd, uint8_t* data, size_t size) {
     size_t so_far = 0;
     while (so_far < size) {
-        ssize_t r = TEMP_FAILURE_RETRY(read(fd, data+so_far, size-so_far));
+        ssize_t r = TEMP_FAILURE_RETRY(ota_read(fd, data+so_far, size-so_far));
         if (r == -1) {
             fprintf(stderr, "read failed: %s\n", strerror(errno));
             return -1;
@@ -156,7 +157,7 @@
 static int write_all(int fd, const uint8_t* data, size_t size) {
     size_t written = 0;
     while (written < size) {
-        ssize_t w = TEMP_FAILURE_RETRY(write(fd, data+written, size-written));
+        ssize_t w = TEMP_FAILURE_RETRY(ota_write(fd, data+written, size-written));
         if (w == -1) {
             fprintf(stderr, "write failed: %s\n", strerror(errno));
             return -1;
@@ -553,7 +554,7 @@
         return -1;
     }
 
-    int fd = TEMP_FAILURE_RETRY(open(fn.c_str(), O_RDONLY));
+    int fd = TEMP_FAILURE_RETRY(ota_open(fn.c_str(), O_RDONLY));
     unique_fd fd_holder(fd);
 
     if (fd == -1) {
@@ -610,7 +611,7 @@
 
     fprintf(stderr, " writing %d blocks to %s\n", blocks, cn.c_str());
 
-    int fd = TEMP_FAILURE_RETRY(open(fn.c_str(), O_WRONLY | O_CREAT | O_TRUNC, STASH_FILE_MODE));
+    int fd = TEMP_FAILURE_RETRY(ota_open(fn.c_str(), O_WRONLY | O_CREAT | O_TRUNC, STASH_FILE_MODE));
     unique_fd fd_holder(fd);
 
     if (fd == -1) {
@@ -622,7 +623,7 @@
         return -1;
     }
 
-    if (fsync(fd) == -1) {
+    if (ota_fsync(fd) == -1) {
         fprintf(stderr, "fsync \"%s\" failed: %s\n", fn.c_str(), strerror(errno));
         return -1;
     }
@@ -634,7 +635,7 @@
     }
 
     std::string dname = GetStashFileName(base, "", "");
-    int dfd = TEMP_FAILURE_RETRY(open(dname.c_str(), O_RDONLY | O_DIRECTORY));
+    int dfd = TEMP_FAILURE_RETRY(ota_open(dname.c_str(), O_RDONLY | O_DIRECTORY));
     unique_fd dfd_holder(dfd);
 
     if (dfd == -1) {
@@ -642,7 +643,7 @@
         return -1;
     }
 
-    if (fsync(dfd) == -1) {
+    if (ota_fsync(dfd) == -1) {
         fprintf(stderr, "fsync \"%s\" failed: %s\n", dname.c_str(), strerror(errno));
         return -1;
     }
@@ -1346,7 +1347,7 @@
         return StringValue(strdup(""));
     }
 
-    params.fd = TEMP_FAILURE_RETRY(open(blockdev_filename->data, O_RDWR));
+    params.fd = TEMP_FAILURE_RETRY(ota_open(blockdev_filename->data, O_RDWR));
     unique_fd fd_holder(params.fd);
 
     if (params.fd == -1) {
@@ -1465,7 +1466,7 @@
         }
 
         if (params.canwrite) {
-            if (fsync(params.fd) == -1) {
+            if (ota_fsync(params.fd) == -1) {
                 fprintf(stderr, "fsync failed: %s\n", strerror(errno));
                 goto pbiudone;
             }
@@ -1490,7 +1491,7 @@
     rc = 0;
 
 pbiudone:
-    if (fsync(params.fd) == -1) {
+    if (ota_fsync(params.fd) == -1) {
         fprintf(stderr, "fsync failed: %s\n", strerror(errno));
     }
     // params.fd will be automatically closed because of the fd_holder above.
@@ -1614,7 +1615,7 @@
         return StringValue(strdup(""));
     }
 
-    int fd = open(blockdev_filename->data, O_RDWR);
+    int fd = ota_open(blockdev_filename->data, O_RDWR);
     unique_fd fd_holder(fd);
     if (fd < 0) {
         ErrorAbort(state, "open \"%s\" failed: %s", blockdev_filename->data, strerror(errno));
@@ -1668,7 +1669,7 @@
         return StringValue(strdup(""));
     }
 
-    int fd = open(arg_filename->data, O_RDONLY);
+    int fd = ota_open(arg_filename->data, O_RDONLY);
     unique_fd fd_holder(fd);
     if (fd == -1) {
         ErrorAbort(state, "open \"%s\" failed: %s", arg_filename->data, strerror(errno));