diff --git a/js/src/patch.js b/js/src/patch.js
index 8ee3339..4676db8 100644
--- a/js/src/patch.js
+++ b/js/src/patch.js
@@ -223,9 +223,9 @@ Patch.prototype.projectObjects = function (compiledProjection) {
 };
 
 Patch.prototype.pretty = function () {
-  return ("<<<<<<<< Removed:\n" + Trie.prettyTrie(this.removed) + "\n" +
-	  "======== Added:\n" + Trie.prettyTrie(this.added) + "\n" +
-	  ">>>>>>>>");
+  return ("\n" +
+          "-" + Trie.prettyTrie(this.removed, { lineSep: "\n-" }) + "\n" +
+          "+" + Trie.prettyTrie(this.added, { lineSep: "\n+" }) + "\n");
 };
 
 // Completely ignores success-values in t.
diff --git a/js/src/trie.js b/js/src/trie.js
index 4fc8ad3..438f7ab 100644
--- a/js/src/trie.js
+++ b/js/src/trie.js
@@ -837,7 +837,7 @@ function prettyTrie(m, optionsOpt) {
           .sortBy(function (k, key) { return key })
           .forEach(function (k, key) {
 	    if (needSep) {
-	      acc.push("\n");
+	      acc.push(options.lineSep || "\n");
 	      acc.push(indentStr(i));
 	    } else {
 	      needSep = true;