diff --git a/platform/diff-impl/src/com/intellij/diff/tools/external/ExternalDiffToolUtil.java b/platform/diff-impl/src/com/intellij/diff/tools/external/ExternalDiffToolUtil.java
index 2eccc8d703ed..936ee405660f 100644
--- a/platform/diff-impl/src/com/intellij/diff/tools/external/ExternalDiffToolUtil.java
+++ b/platform/diff-impl/src/com/intellij/diff/tools/external/ExternalDiffToolUtil.java
@@ -129,7 +129,7 @@ public class ExternalDiffToolUtil {
 
     byte[] bytes = contentData.getBytes(charset);
 
-    byte[] bom = hasBom ? CharsetToolkit.getBom(charset) : null;
+    byte[] bom = hasBom ? CharsetToolkit.getPossibleBom(charset) : null;
     if (bom != null) {
       bytes = ArrayUtil.mergeArrays(bom, bytes);
     }
diff --git a/platform/util/src/com/intellij/openapi/vfs/CharsetToolkit.java b/platform/util/src/com/intellij/openapi/vfs/CharsetToolkit.java
index 178936acf6ec..b8f94ab9e12e 100644
--- a/platform/util/src/com/intellij/openapi/vfs/CharsetToolkit.java
+++ b/platform/util/src/com/intellij/openapi/vfs/CharsetToolkit.java
@@ -624,8 +624,12 @@ public class CharsetToolkit {
     return CHARSET_TO_MANDATORY_BOM.get(charset);
   }
 
+  /**
+   * @return BOM which can be associated with this charset, or null otherwise.
+   *         Currently these are UTF-16xx, UTF-32xx and UTF-8.
+   */
   @Nullable
-  public static byte[] getBom(@NotNull Charset charset) {
+  public static byte[] getPossibleBom(@NotNull Charset charset) {
     if (charset.equals(UTF8_CHARSET)) return UTF8_BOM;
     return CHARSET_TO_MANDATORY_BOM.get(charset);
   }