diff --git a/init/builtins.cpp b/init/builtins.cpp
index 42cfa43..9f3dcc1 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -389,7 +389,7 @@
             return -1;
         }
 
-        sprintf(tmp, "/dev/block/mtdblock%d", n);
+        snprintf(tmp, sizeof(tmp), "/dev/block/mtdblock%d", n);
 
         if (wait)
             wait_for_file(tmp, COMMAND_RETRY_TIMEOUT);
@@ -409,7 +409,7 @@
         }
 
         for (n = 0; ; n++) {
-            sprintf(tmp, "/dev/block/loop%d", n);
+            snprintf(tmp, sizeof(tmp), "/dev/block/loop%d", n);
             loop = open(tmp, mode | O_CLOEXEC);
             if (loop < 0) {
                 close(fd);
diff --git a/init/devices.cpp b/init/devices.cpp
index 9275439..3a9b753 100644
--- a/init/devices.cpp
+++ b/init/devices.cpp
@@ -152,7 +152,7 @@
         if ((strlen(upath) + strlen(dp->attr) + 6) > sizeof(buf))
             break;
 
-        sprintf(buf,"/sys%s/%s", upath, dp->attr);
+        snprintf(buf, sizeof(buf), "/sys%s/%s", upath, dp->attr);
         INFO("fixup %s %d %d 0%o\n", buf, dp->uid, dp->gid, dp->perm);
         chown(buf, dp->uid, dp->gid);
         chmod(buf, dp->perm);
diff --git a/init/init.cpp b/init/init.cpp
index 8647496..41ceb0a 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -252,7 +252,7 @@
         umask(077);
         if (properties_inited()) {
             get_property_workspace(&fd, &sz);
-            sprintf(tmp, "%d,%d", dup(fd), sz);
+            snprintf(tmp, sizeof(tmp), "%d,%d", dup(fd), sz);
             add_environment("ANDROID_PROPERTY_WORKSPACE", tmp);
         }