diff --git a/src/components/datetime/DateTimeController.cpp b/src/components/datetime/DateTimeController.cpp
index 9e9fb6e4..8d4a834e 100644
--- a/src/components/datetime/DateTimeController.cpp
+++ b/src/components/datetime/DateTimeController.cpp
@@ -140,9 +140,9 @@ std::string DateTime::FormattedTime() {
       hour12 = (hour == 12) ? 12 : hour - 12;
       amPmStr = "PM";
     }
-    sprintf(buff, "%i:%02i %s", hour12, minute, amPmStr);
+    snprintf(buff, sizeof(buff), "%i:%02i %s", hour12, minute, amPmStr);
   } else {
-    sprintf(buff, "%02i:%02i", hour, minute);
+    snprintf(buff, sizeof(buff), "%02i:%02i", hour, minute);
   }
   return std::string(buff);
 }
diff --git a/src/displayapp/screens/StopWatch.cpp b/src/displayapp/screens/StopWatch.cpp
index 239ebe39..d2b81154 100644
--- a/src/displayapp/screens/StopWatch.cpp
+++ b/src/displayapp/screens/StopWatch.cpp
@@ -198,11 +198,11 @@ void StopWatch::stopLapBtnEventHandler() {
         continue;
       }
       TimeSeparated_t times = convertTicksToTimeSegments(laps[i]);
-      char buffer[16];
+      char buffer[17];
       if (times.hours == 0) {
-        sprintf(buffer, "#%2d   %2d:%02d.%02d\n", i + 1, times.mins, times.secs, times.hundredths);
+        snprintf(buffer, sizeof(buffer), "#%2d   %2d:%02d.%02d\n", i + 1, times.mins, times.secs, times.hundredths);
       } else {
-        sprintf(buffer, "#%2d %2d:%02d:%02d.%02d\n", i + 1, times.hours, times.mins, times.secs, times.hundredths);
+        snprintf(buffer, sizeof(buffer), "#%2d %2d:%02d:%02d.%02d\n", i + 1, times.hours, times.mins, times.secs, times.hundredths);
       }
       lv_label_ins_text(lapText, LV_LABEL_POS_LAST, buffer);
     }
diff --git a/src/displayapp/screens/SystemInfo.cpp b/src/displayapp/screens/SystemInfo.cpp
index eea75938..18fb7ad2 100644
--- a/src/displayapp/screens/SystemInfo.cpp
+++ b/src/displayapp/screens/SystemInfo.cpp
@@ -236,9 +236,9 @@ std::unique_ptr<Screen> SystemInfo::CreateScreen4() {
   auto nb = uxTaskGetSystemState(tasksStatus, maxTaskCount, nullptr);
   std::sort(tasksStatus, tasksStatus + nb, sortById);
   for (uint8_t i = 0; i < nb && i < maxTaskCount; i++) {
-    char buffer[7] = {0};
+    char buffer[11] = {0};
 
-    sprintf(buffer, "%lu", tasksStatus[i].xTaskNumber);
+    snprintf(buffer, sizeof(buffer), "%lu", tasksStatus[i].xTaskNumber);
     lv_table_set_cell_value(infoTask, i + 1, 0, buffer);
     switch (tasksStatus[i].eCurrentState) {
       case eReady:
@@ -262,9 +262,9 @@ std::unique_ptr<Screen> SystemInfo::CreateScreen4() {
     lv_table_set_cell_value(infoTask, i + 1, 1, buffer);
     lv_table_set_cell_value(infoTask, i + 1, 2, tasksStatus[i].pcTaskName);
     if (tasksStatus[i].usStackHighWaterMark < 20) {
-      sprintf(buffer, "%d low", tasksStatus[i].usStackHighWaterMark);
+      snprintf(buffer, sizeof(buffer), "%" PRIu16 " low", tasksStatus[i].usStackHighWaterMark);
     } else {
-      sprintf(buffer, "%d", tasksStatus[i].usStackHighWaterMark);
+      snprintf(buffer, sizeof(buffer), "%" PRIu16, tasksStatus[i].usStackHighWaterMark);
     }
     lv_table_set_cell_value(infoTask, i + 1, 3, buffer);
   }
diff --git a/src/displayapp/screens/Twos.cpp b/src/displayapp/screens/Twos.cpp
index 8157a160..6f2eff40 100644
--- a/src/displayapp/screens/Twos.cpp
+++ b/src/displayapp/screens/Twos.cpp
@@ -242,7 +242,7 @@ void Twos::updateGridDisplay() {
     const unsigned int col = i % nCols;
     if (grid[row][col].value > 0) {
       char buffer[7];
-      sprintf(buffer, "%d", grid[row][col].value);
+      snprintf(buffer, sizeof(buffer), "%u", grid[row][col].value);
       lv_table_set_cell_value(gridDisplay, row, col, buffer);
     } else {
       lv_table_set_cell_value(gridDisplay, row, col, "");
diff --git a/src/displayapp/screens/settings/SettingDisplay.cpp b/src/displayapp/screens/settings/SettingDisplay.cpp
index 91f4d590..9abb4c74 100644
--- a/src/displayapp/screens/settings/SettingDisplay.cpp
+++ b/src/displayapp/screens/settings/SettingDisplay.cpp
@@ -46,7 +46,7 @@ SettingDisplay::SettingDisplay(Pinetime::Applications::DisplayApp* app, Pinetime
   char buffer[12];
   for (unsigned int i = 0; i < options.size(); i++) {
     cbOption[i] = lv_checkbox_create(container1, nullptr);
-    sprintf(buffer, "%2ds", options[i] / 1000);
+    snprintf(buffer, sizeof(buffer), "%2" PRIu16 "s", options[i] / 1000);
     lv_checkbox_set_text(cbOption[i], buffer);
     cbOption[i]->user_data = this;
     lv_obj_set_event_cb(cbOption[i], event_handler);