diff --git a/src/org/thoughtcrime/securesms/VerifyIdentityActivity.java b/src/org/thoughtcrime/securesms/VerifyIdentityActivity.java
index 66e36e97a0..cc425b167b 100644
--- a/src/org/thoughtcrime/securesms/VerifyIdentityActivity.java
+++ b/src/org/thoughtcrime/securesms/VerifyIdentityActivity.java
@@ -36,7 +36,6 @@ import android.os.Bundle;
 import android.os.Vibrator;
 import androidx.annotation.DrawableRes;
 import androidx.annotation.NonNull;
-import androidx.annotation.RequiresApi;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentTransaction;
 import androidx.appcompat.widget.SwitchCompat;
@@ -89,6 +88,7 @@ import org.whispersystems.libsignal.fingerprint.NumericFingerprintGenerator;
 
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.Charset;
+import java.util.Locale;
 
 import static org.whispersystems.libsignal.SessionCipher.SESSION_LOCK;
 
@@ -487,11 +487,10 @@ public class VerifyIdentityActivity extends PassphraseRequiredActionBarActivity
       valueAnimator.setObjectValues(0, Integer.parseInt(segment));
 
       valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
-        @RequiresApi(api = Build.VERSION_CODES.HONEYCOMB)
         @Override
         public void onAnimationUpdate(ValueAnimator animation) {
           int value = (int) animation.getAnimatedValue();
-          codeView.setText(String.format("%05d", value));
+          codeView.setText(String.format(Locale.getDefault(), "%05d", value));
         }
       });
 
diff --git a/src/org/thoughtcrime/securesms/components/AudioView.java b/src/org/thoughtcrime/securesms/components/AudioView.java
index d5ea649223..2cb0b51863 100644
--- a/src/org/thoughtcrime/securesms/components/AudioView.java
+++ b/src/org/thoughtcrime/securesms/components/AudioView.java
@@ -33,6 +33,7 @@ import org.thoughtcrime.securesms.mms.AudioSlide;
 import org.thoughtcrime.securesms.mms.SlideClickListener;
 
 import java.io.IOException;
+import java.util.Locale;
 import java.util.concurrent.TimeUnit;
 
 
@@ -193,7 +194,7 @@ public class AudioView extends FrameLayout implements AudioSlidePlayer.Listener
     if (seekProgress > seekBar.getProgress() || backwardsCounter > 3) {
       backwardsCounter = 0;
       this.seekBar.setProgress(seekProgress);
-      this.timestamp.setText(String.format("%02d:%02d",
+      this.timestamp.setText(String.format(Locale.getDefault(), "%02d:%02d",
                                            TimeUnit.MILLISECONDS.toMinutes(millis),
                                            TimeUnit.MILLISECONDS.toSeconds(millis)));
     } else {
diff --git a/src/org/thoughtcrime/securesms/components/camera/CameraUtils.java b/src/org/thoughtcrime/securesms/components/camera/CameraUtils.java
index 8feaa8fb13..8e715b7499 100644
--- a/src/org/thoughtcrime/securesms/components/camera/CameraUtils.java
+++ b/src/org/thoughtcrime/securesms/components/camera/CameraUtils.java
@@ -15,6 +15,7 @@ import java.util.Collections;
 import java.util.Comparator;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Locale;
 
 @SuppressWarnings("deprecation")
 public class CameraUtils {
@@ -30,7 +31,8 @@ public class CameraUtils {
     final int    targetHeight = displayOrientation % 180 == 90 ? width  : height;
     final double targetRatio  = (double) targetWidth / targetHeight;
 
-    Log.d(TAG, String.format("getPreferredPreviewSize(%d, %d, %d) -> target %dx%d, AR %.02f",
+    Log.d(TAG, String.format(Locale.US,
+                             "getPreferredPreviewSize(%d, %d, %d) -> target %dx%d, AR %.02f",
                              displayOrientation, width, height,
                              targetWidth, targetHeight, targetRatio));
 
@@ -39,7 +41,7 @@ public class CameraUtils {
     List<Size> bigEnough = new LinkedList<>();
 
     for (Size size : sizes) {
-      Log.d(TAG, String.format("  %dx%d (%.02f)", size.width, size.height, (float)size.width / size.height));
+      Log.d(TAG, String.format(Locale.US, "  %dx%d (%.02f)", size.width, size.height, (float)size.width / size.height));
 
       if (size.height == size.width * targetRatio && size.height >= targetHeight && size.width >= targetWidth) {
         ideals.add(size);
diff --git a/src/org/thoughtcrime/securesms/database/EarlyReceiptCache.java b/src/org/thoughtcrime/securesms/database/EarlyReceiptCache.java
index d29eee9ec4..c33cef405d 100644
--- a/src/org/thoughtcrime/securesms/database/EarlyReceiptCache.java
+++ b/src/org/thoughtcrime/securesms/database/EarlyReceiptCache.java
@@ -4,6 +4,7 @@ import org.thoughtcrime.securesms.logging.Log;
 import org.thoughtcrime.securesms.util.LRUCache;
 
 import java.util.HashMap;
+import java.util.Locale;
 import java.util.Map;
 
 public class EarlyReceiptCache {
@@ -14,7 +15,7 @@ public class EarlyReceiptCache {
 
   public synchronized void increment(long timestamp, Address origin) {
     Log.i(TAG, this+"");
-    Log.i(TAG, String.format("Early receipt: (%d, %s)", timestamp, origin.serialize()));
+    Log.i(TAG, String.format(Locale.US, "Early receipt: (%d, %s)", timestamp, origin.serialize()));
 
     Map<Address, Long> receipts = cache.get(timestamp);
 
@@ -37,7 +38,7 @@ public class EarlyReceiptCache {
     Map<Address, Long> receipts = cache.remove(timestamp);
 
     Log.i(TAG, this+"");
-    Log.i(TAG, String.format("Checking early receipts (%d): %d", timestamp, receipts == null ? 0 : receipts.size()));
+    Log.i(TAG, String.format(Locale.US, "Checking early receipts (%d): %d", timestamp, receipts == null ? 0 : receipts.size()));
 
     return receipts != null ? receipts : new HashMap<>();
   }
diff --git a/src/org/thoughtcrime/securesms/jobmanager/JobLogger.java b/src/org/thoughtcrime/securesms/jobmanager/JobLogger.java
index c35f6dc1ac..9e664d1f53 100644
--- a/src/org/thoughtcrime/securesms/jobmanager/JobLogger.java
+++ b/src/org/thoughtcrime/securesms/jobmanager/JobLogger.java
@@ -3,6 +3,8 @@ package org.thoughtcrime.securesms.jobmanager;
 import androidx.annotation.NonNull;
 import android.text.TextUtils;
 
+import java.util.Locale;
+
 public class JobLogger {
 
   public static String format(@NonNull Job job, @NonNull String event) {
@@ -18,7 +20,8 @@ public class JobLogger {
                                                                                                   : String.valueOf(job.getParameters().getMaxAttempts());
     String lifespan            = job.getParameters().getLifespan() == Job.Parameters.IMMORTAL ? "Immortal"
                                                                                               : String.valueOf(job.getParameters().getLifespan()) + " ms";
-    return String.format("[%s][%s]%s %s (Time Since Submission: %d ms, Lifespan: %s, Run Attempt: %d/%s)",
+    return String.format(Locale.US,
+                         "[%s][%s]%s %s (Time Since Submission: %d ms, Lifespan: %s, Run Attempt: %d/%s)",
                          id, job.getClass().getSimpleName(), tag, event, timeSinceSubmission, lifespan, runAttempt, maxAttempts);
   }
 }
diff --git a/src/org/thoughtcrime/securesms/preferences/AppProtectionPreferenceFragment.java b/src/org/thoughtcrime/securesms/preferences/AppProtectionPreferenceFragment.java
index 89f3342b76..7ec5fcf177 100644
--- a/src/org/thoughtcrime/securesms/preferences/AppProtectionPreferenceFragment.java
+++ b/src/org/thoughtcrime/securesms/preferences/AppProtectionPreferenceFragment.java
@@ -27,6 +27,7 @@ import org.thoughtcrime.securesms.util.CommunicationActions;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
 import org.whispersystems.signalservice.api.SignalServiceAccountManager;
 
+import java.util.Locale;
 import java.util.concurrent.TimeUnit;
 
 import javax.inject.Inject;
@@ -103,7 +104,7 @@ public class AppProtectionPreferenceFragment extends CorrectedPreferenceFragment
 
     findPreference(TextSecurePreferences.SCREEN_LOCK_TIMEOUT)
         .setSummary(timeoutSeconds <= 0 ? getString(R.string.AppProtectionPreferenceFragment_none) :
-                                          String.format("%02d:%02d:%02d", hours, minutes, seconds));
+                                          String.format(Locale.getDefault(), "%02d:%02d:%02d", hours, minutes, seconds));
   }
 
   private void initializeVisibility() {