diff --git a/lib/nodeSass/AutoFixer.js b/lib/nodeSass/AutoFixer.js
index ea1c66ad..c36ec691 100644
--- a/lib/nodeSass/AutoFixer.js
+++ b/lib/nodeSass/AutoFixer.js
@@ -10,10 +10,12 @@ const cssCompiler = require('../css/compile');
 const BaseRulesFixer = require('./BaseRulesFixer');
 const ConditionaImportFixer = require('./ConditionalImportFixer');
 const CommaRemovalFixer = require('./CommaRemovalFixer');
+const UndefinedVariableFixer = require('./UndefinedVariableFixer');
 
 const CONDITIONAL_IMPORT = 'conditional-import';
 const BASE_LEVEL_RULES = 'base-level-rules';
 const POSSIBLE_WRONG_COMMA = 'possible-wrong-comma';
+const UNDEFINED_VARIABLE = 'undefined-variable';
 
 class AutoFixer {
     /**
@@ -75,13 +77,17 @@ class AutoFixer {
                 const toFixFile = err.file === 'stdin' ? file : err.file;
                 const commaRemovalFixer = new CommaRemovalFixer(dirname, toFixFile);
                 files = await commaRemovalFixer.run();
+            } else if (problem === UNDEFINED_VARIABLE) {
+                const toFixFile = err.file === 'stdin' ? file : err.file;
+                const fixer = new UndefinedVariableFixer(dirname, toFixFile);
+                files = await fixer.run(err.message);
             }
             this.parseChangedFiles(files);
         } else {
             const filePath = path.join(this.themePath, 'assets/scss', file + '.scss');
             console.log("Couldn't determine and autofix the problem. Please fix it manually.".red);
-            console.log('Found trying compile file:'.red, filePath);
-            throw new Error(err);
+            console.log('Found trying to compile file:'.red, filePath);
+            throw new Error(err.formatted ? err.formatted : err);
         }
     }
 
@@ -107,6 +113,9 @@ class AutoFixer {
             ) {
                 return POSSIBLE_WRONG_COMMA;
             }
+            if (err.formatted.includes('Undefined variable')) {
+                return UNDEFINED_VARIABLE;
+            }
         }
 
         return null;
diff --git a/lib/nodeSass/BaseRulesFixer.js b/lib/nodeSass/BaseRulesFixer.js
index e983a888..2d7cfb51 100644
--- a/lib/nodeSass/BaseRulesFixer.js
+++ b/lib/nodeSass/BaseRulesFixer.js
@@ -16,7 +16,10 @@ class BaseRulesFixer extends BaseFixer {
         return {
             postcssPlugin: 'Transform Base Rules Issues into Comments',
             Rule(rule, { Comment }) {
-                if (rule.parent.type === 'root' && rule.selector.startsWith('&--')) {
+                if (
+                    rule.parent.type === 'root' &&
+                    (rule.selector.startsWith('&--') || rule.selector.startsWith('&.'))
+                ) {
                     const comment = new Comment({ text: rule.toString() });
                     rule.replaceWith(comment);
                 }
diff --git a/lib/nodeSass/UndefinedVariableFixer.js b/lib/nodeSass/UndefinedVariableFixer.js
new file mode 100644
index 00000000..56a49f66
--- /dev/null
+++ b/lib/nodeSass/UndefinedVariableFixer.js
@@ -0,0 +1,60 @@
+const fs = require('fs');
+const BaseFixer = require('./BaseFixer');
+
+class UndefinedVariableFixer extends BaseFixer {
+    async run(errorMessage) {
+        const varName = this.getUndefinedVariableName(errorMessage);
+        const value = await this.guessVariableValue(varName);
+
+        const scss = fs.readFileSync(this.filePath, 'utf8');
+        const processedFile = await this.processCss(scss, this.transform(varName, value));
+
+        return [{ filePath: this.filePath, data: processedFile.css }];
+    }
+
+    getUndefinedVariableName(errorMessage) {
+        const match = errorMessage.match(/\$([a-zA-Z]{1,})/gi);
+        if (!match) {
+            throw new Error("Couldn't detemine undefined variable name!");
+        }
+        return match[0];
+    }
+
+    transform(varName, value) {
+        return {
+            postcssPlugin: 'Declare unvariable variable value',
+            Once(root, { Declaration }) {
+                const newRule = new Declaration({
+                    value,
+                    prop: varName,
+                    source: '',
+                });
+                root.prepend(newRule);
+            },
+        };
+    }
+
+    async guessVariableValue(varName) {
+        const scss = fs.readFileSync(this.filePath, 'utf8');
+        const processedFile = await this.processCss(
+            scss,
+            this.transformForGuessingVariableValue(varName),
+        );
+        return processedFile.varValue;
+    }
+
+    transformForGuessingVariableValue(varName) {
+        return {
+            postcssPlugin: 'Get first variable value found in the file',
+            Declaration: (decl, { result }) => {
+                if (decl.prop === varName) {
+                    // eslint-disable-next-line no-param-reassign
+                    result.varValue = decl.value;
+                    // todo propertly break on first found declaration
+                }
+            },
+        };
+    }
+}
+
+module.exports = UndefinedVariableFixer;