diff --git a/tools/catalog.js b/tools/catalog.js
index 2036f1cf65..2b2021f12d 100644
--- a/tools/catalog.js
+++ b/tools/catalog.js
@@ -185,15 +185,19 @@ _.extend(Catalog.prototype, {
         if (!constraint.weak) {
           deps.push(constraint.packageName);
         }
-        constr.push(constraint);
+        if (constraint.version) {
+          constr.push(constraint);
+        }
       });
     } else {
       _.each(constraints, function (constraint, packageName) {
         deps.push(packageName);
-        var utils = require('./utils.js');
-        var vers = utils.parseConstraint(constraint);
-        vers['packageName'] = packageName;
-        constr.push(vers);
+        if (constraint) {
+          var utils = require('./utils.js');
+          var vers = utils.parseConstraint(constraint);
+          vers['packageName'] = packageName;
+          constr.push(vers);
+        }
      });
     }
     // The constraint solver has been initialized, so we can just call it.
diff --git a/tools/compiler.js b/tools/compiler.js
index 3ba0b51290..99853e65f1 100644
--- a/tools/compiler.js
+++ b/tools/compiler.js
@@ -937,7 +937,7 @@ compiler.checkUpToDate = function (packageSource, unipackage) {
       // For each plugin, check that the resolved build-time deps for
       // that plugin match the unipackage's build time deps for it.
       var packageLoaderForPlugin = new PackageLoader({
-        versions: buildTimeDeps.pluginDependencies
+        versions: buildTimeDeps.pluginDependencies[pluginName]
       });
       var unipackagePluginDeps = unipackage.buildTimePluginDependencies[pluginName];
       if (! unipackagePluginDeps ||