diff --git a/Loop.cpp b/Loop.cpp
index a5863b3..1127817 100644
--- a/Loop.cpp
+++ b/Loop.cpp
@@ -47,7 +47,7 @@
         struct loop_info64 li;
         int rc;
 
-        sprintf(filename, "/dev/block/loop%d", i);
+        snprintf(filename, sizeof(filename), "/dev/block/loop%d", i);
 
         if ((fd = open(filename, O_RDWR | O_CLOEXEC)) < 0) {
             if (errno != ENOENT) {
@@ -91,7 +91,7 @@
         struct loop_info64 li;
         int rc;
 
-        sprintf(filename, "/dev/block/loop%d", i);
+        snprintf(filename, sizeof(filename), "/dev/block/loop%d", i);
 
         if ((fd = open(filename, O_RDWR | O_CLOEXEC)) < 0) {
             if (errno != ENOENT) {
@@ -137,7 +137,7 @@
         int rc;
         char *secontext = NULL;
 
-        sprintf(filename, "/dev/block/loop%d", i);
+        snprintf(filename, sizeof(filename), "/dev/block/loop%d", i);
 
         /*
          * The kernel starts us off with 8 loop nodes, but more