diff --git a/package.json b/package.json
index e9889de4e..2980fdce5 100644
--- a/package.json
+++ b/package.json
@@ -7,12 +7,10 @@
     "type": "git",
     "url": "https://github.com/mathquill/mathquill.git"
   },
-  "dependencies": {
-    "pjs": "3.x"
-  },
   "devDependencies": {
-    "mocha": "*",
-    "uglify-js": "2.x",
-    "less": ">=1.5.1"
+    "less": ">=1.5.1 <3.0.0",
+    "mocha": ">=2.4.1",
+    "pjs": ">=3.1.0 <5.0.0",
+    "uglify-js": "2.x"
   }
 }
diff --git a/src/commands/math/advancedSymbols.js b/src/commands/math/advancedSymbols.js
index 776b9a7f5..3827e72b1 100644
--- a/src/commands/math/advancedSymbols.js
+++ b/src/commands/math/advancedSymbols.js
@@ -172,6 +172,7 @@ LatexCmds.hookrightarrow = bind(VanillaSymbol, '\\hookrightarrow ', '&#8618;');
 LatexCmds.searrow = bind(VanillaSymbol, '\\searrow ', '&#8600;');
 LatexCmds.leftharpoonup = bind(VanillaSymbol, '\\leftharpoonup ', '&#8636;');
 LatexCmds.rightharpoonup = bind(VanillaSymbol, '\\rightharpoonup ', '&#8640;');
+LatexCmds.rightleftharpoons = bind(VanillaSymbol, '\\rightleftharpoons ', '&#8652;');
 LatexCmds.swarrow = bind(VanillaSymbol, '\\swarrow ', '&#8601;');
 LatexCmds.leftharpoondown = bind(VanillaSymbol, '\\leftharpoondown ', '&#8637;');
 LatexCmds.rightharpoondown = bind(VanillaSymbol, '\\rightharpoondown ', '&#8641;');
diff --git a/src/symbols.js b/src/symbols.js
index 1e1899686..00670c0c7 100644
--- a/src/symbols.js
+++ b/src/symbols.js
@@ -422,6 +422,7 @@ LatexCmds.hookrightarrow = bind(VanillaSymbol, '\\hookrightarrow ', '&#8618;');
 LatexCmds.searrow = bind(VanillaSymbol, '\\searrow ', '&#8600;');
 LatexCmds.leftharpoonup = bind(VanillaSymbol, '\\leftharpoonup ', '&#8636;');
 LatexCmds.rightharpoonup = bind(VanillaSymbol, '\\rightharpoonup ', '&#8640;');
+LatexCmds.rightleftharpoons = bind(VanillaSymbol, '\\rightleftharpoons ', '&#8652;');
 LatexCmds.swarrow = bind(VanillaSymbol, '\\swarrow ', '&#8601;');
 LatexCmds.leftharpoondown = bind(VanillaSymbol, '\\leftharpoondown ', '&#8637;');
 LatexCmds.rightharpoondown = bind(VanillaSymbol, '\\rightharpoondown ', '&#8641;');