diff --git a/src/com/android/email/mail/store/imap/ImapConstants.java b/src/com/android/email/mail/store/imap/ImapConstants.java
index eee2ac44e..658dcd837 100644
--- a/src/com/android/email/mail/store/imap/ImapConstants.java
+++ b/src/com/android/email/mail/store/imap/ImapConstants.java
@@ -18,13 +18,15 @@ package com.android.email.mail.store.imap;
 
 import com.android.email.mail.Store;
 
+import java.util.Locale;
+
 public final class ImapConstants {
     private ImapConstants() {}
 
     public static final String FETCH_FIELD_BODY_PEEK_BARE = "BODY.PEEK";
     public static final String FETCH_FIELD_BODY_PEEK = FETCH_FIELD_BODY_PEEK_BARE + "[]";
     public static final String FETCH_FIELD_BODY_PEEK_SANE
-            = String.format("BODY.PEEK[]<0.%d>", Store.FETCH_BODY_SANE_SUGGESTED_SIZE);
+            = String.format(Locale.US, "BODY.PEEK[]<0.%d>", Store.FETCH_BODY_SANE_SUGGESTED_SIZE);
     public static final String FETCH_FIELD_HEADERS =
             "BODY.PEEK[HEADER.FIELDS (date subject from content-type to cc message-id)]";