diff --git a/src/assert.js b/src/assert.js
index ad55436..de74169 100644
--- a/src/assert.js
+++ b/src/assert.js
@@ -70,8 +70,8 @@ exports.trbl = (raw, name, _default=0) => units => {
 
 exports.asym = (raw, name) => {
     // allow different aliases
-    source_aliases = ['source', 'origin', 'base', 'primary', 'left']
-    clone_aliases = ['clone', 'image', 'derived', 'secondary', 'right']
+    const source_aliases = ['source', 'origin', 'base', 'primary', 'left']
+    const clone_aliases = ['clone', 'image', 'derived', 'secondary', 'right']
     _in(raw, name, ['both'].concat(source_aliases, clone_aliases))
     // return aliases to canonical names
     if (source_aliases.includes(raw)) return 'source'
diff --git a/src/filter.js b/src/filter.js
index ba7f5e7..f97a761 100644
--- a/src/filter.js
+++ b/src/filter.js
@@ -128,7 +128,7 @@ exports.parse = (config, name, points={}, units={}, asym='source') => {
         
         // otherwise, it is treated as a condition to filter all available points
     } else {
-        source = Object.values(points).filter(complex(config, name, units))
+        const source = Object.values(points).filter(complex(config, name, units))
         if (['source', 'both'].includes(asym)) {
             result = result.concat(source)
         }