diff --git a/library/src/main/java/com/google/android/exoplayer/dash/mpd/UrlTemplate.java b/library/src/main/java/com/google/android/exoplayer/dash/mpd/UrlTemplate.java
index c055b460b2..1439ee6ec6 100644
--- a/library/src/main/java/com/google/android/exoplayer/dash/mpd/UrlTemplate.java
+++ b/library/src/main/java/com/google/android/exoplayer/dash/mpd/UrlTemplate.java
@@ -15,6 +15,8 @@
  */
 package com.google.android.exoplayer.dash.mpd;
 
+import java.util.Locale;
+
 /**
  * A template from which URLs can be built.
  * <p>
@@ -85,11 +87,11 @@ public final class UrlTemplate {
       if (identifiers[i] == REPRESENTATION_ID) {
         builder.append(representationId);
       } else if (identifiers[i] == NUMBER_ID) {
-        builder.append(String.format(identifierFormatTags[i], segmentNumber));
+        builder.append(String.format(Locale.US, identifierFormatTags[i], segmentNumber));
       } else if (identifiers[i] == BANDWIDTH_ID) {
-        builder.append(String.format(identifierFormatTags[i], bandwidth));
+        builder.append(String.format(Locale.US, identifierFormatTags[i], bandwidth));
       } else if (identifiers[i] == TIME_ID) {
-        builder.append(String.format(identifierFormatTags[i], time));
+        builder.append(String.format(Locale.US, identifierFormatTags[i], time));
       }
     }
     builder.append(urlPieces[identifierCount]);
diff --git a/library/src/main/java/com/google/android/exoplayer/hls/HlsParserUtil.java b/library/src/main/java/com/google/android/exoplayer/hls/HlsParserUtil.java
index 2ddfdd081b..23a64163ad 100644
--- a/library/src/main/java/com/google/android/exoplayer/hls/HlsParserUtil.java
+++ b/library/src/main/java/com/google/android/exoplayer/hls/HlsParserUtil.java
@@ -36,7 +36,7 @@ import java.util.regex.Pattern;
     if (matcher.find() && matcher.groupCount() == 1) {
       return matcher.group(1);
     }
-    throw new ParserException(String.format("Couldn't match %s tag in %s", tag, line));
+    throw new ParserException("Couldn't match " + tag + " tag in " + line);
   }
 
   public static int parseIntAttr(String line, Pattern pattern, String tag)
diff --git a/library/src/main/java/com/google/android/exoplayer/metadata/Id3Parser.java b/library/src/main/java/com/google/android/exoplayer/metadata/Id3Parser.java
index d2443d7d74..f306c5d6e8 100644
--- a/library/src/main/java/com/google/android/exoplayer/metadata/Id3Parser.java
+++ b/library/src/main/java/com/google/android/exoplayer/metadata/Id3Parser.java
@@ -22,6 +22,7 @@ import com.google.android.exoplayer.util.ParsableByteArray;
 import java.io.UnsupportedEncodingException;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.Locale;
 import java.util.Map;
 
 /**
@@ -108,7 +109,7 @@ public class Id3Parser implements MetadataParser<Map<String, Object>> {
         metadata.put(GeobMetadata.TYPE, new GeobMetadata(mimeType, filename,
             description, objectData));
       } else {
-        String type = String.format("%c%c%c%c", frameId0, frameId1, frameId2, frameId3);
+        String type = String.format(Locale.US, "%c%c%c%c", frameId0, frameId1, frameId2, frameId3);
         byte[] frame = new byte[frameSize];
         id3Data.readBytes(frame, 0, frameSize);
         metadata.put(type, frame);
@@ -165,7 +166,7 @@ public class Id3Parser implements MetadataParser<Map<String, Object>> {
     int id2 = id3Buffer.readUnsignedByte();
     int id3 = id3Buffer.readUnsignedByte();
     if (id1 != 'I' || id2 != 'D' || id3 != '3') {
-      throw new ParserException(String.format(
+      throw new ParserException(String.format(Locale.US,
           "Unexpected ID3 file identifier, expected \"ID3\", actual \"%c%c%c\".", id1, id2, id3));
     }
     id3Buffer.skipBytes(2); // Skip version.
diff --git a/library/src/main/java/com/google/android/exoplayer/util/Util.java b/library/src/main/java/com/google/android/exoplayer/util/Util.java
index 51832cc500..4599d6ecbc 100644
--- a/library/src/main/java/com/google/android/exoplayer/util/Util.java
+++ b/library/src/main/java/com/google/android/exoplayer/util/Util.java
@@ -573,7 +573,7 @@ public final class Util {
   public static String getHexStringFromBytes(byte[] data, int beginIndex, int endIndex) {
     StringBuffer dataStringBuffer = new StringBuffer(endIndex - beginIndex);
     for (int i = beginIndex; i < endIndex; i++) {
-      dataStringBuffer.append(String.format("%02X", data[i]));
+      dataStringBuffer.append(String.format(Locale.US, "%02X", data[i]));
     }
     return dataStringBuffer.toString();
   }