Autoprefixer with Foundation Framework issue

I'm attempting to get autoprefixer working with my setup. Here is the relevant gulpfile section:

// Compile Sass file to CSS, and updates browsers.
gulp.task('sass', function() {
    return gulp.src(sassSource)
        .pipe(plumber())
        .pipe(sourcemaps.init())  // Process the original sources
            .pipe(autoprefixer, {
                browsers: [
                    'last 2 versions',
                    'ie 8',
                    'ie 9',
                    'android 2.3',
                    'android 4',
                    'opera 12'
                ]
            })
            .pipe(sass({outputStyle: 'compressed'}))
        .pipe(sourcemaps.write('./')) // Add the map to modified source.
        .pipe(gulp.dest(sassDestination))
        .pipe(reload({stream:true}));
});

Here is the error message:

TypeError: Object function (opts) {
    return through.obj(function (file, enc, cb) {
        if (file.isNull()) {
            cb(null, file);
            return;
        }

        if (file.isStream()) {
            cb(new gutil.PluginError('gulp-autoprefixer', 'Streaming not supported'));
            return;
        }

        var fileOpts = objectAssign({}, opts);
        var processor = postcss()
            .use(autoprefixer(fileOpts))
            .process(file.contents.toString(), {
                map: file.sourceMap ? {annotation: false} : false,
                from: file.path,
                to: file.path
            });

        processor.then(function (res) {
            file.contents = new Buffer(res.css);

            if (res.map && file.sourceMap) {
                applySourceMap(file, res.map.toString());
            }

            var warnings = res.warnings();

            if (warnings.length > 0) {
                gutil.log('gulp-autoprefixer:', '\n  ' + warnings.join('\n  '));
            }

            cb(null, file);
        }).catch(function (err) {
            var cssError = err.name === 'CssSyntaxError';

            if (cssError) {
                err.message = err.message + err.showSourceCode();
            }

            // prevent stream unhandled exception from being suppressed by Promise
            setImmediate(cb, new gutil.PluginError('gulp-autoprefixer', err, {
                fileName: file.path,
                showStack: !cssError
            }));
        });
    });
} has no method 'on'
    at DestroyableTransform.Readable.pipe [as _pipe] (/Applications/AMPPS/www/jump_start/wp-content/themes/jumpstart/node_modules/gulp-sourcemaps/node_modules/through2/node_modules/readable-stream/lib/_stream_readable.js:516:8)
    at DestroyableTransform.pipe2 (/Applications/AMPPS/www/jump_start/wp-content/themes/jumpstart/node_modules/gulp-plumber/index.js:70:20)
    at Gulp.gulp.task.gulp.src.pipe.pipe.pipe.reload.stream (/Applications/AMPPS/www/jump_start/wp-content/themes/jumpstart/gulpfile.js:46:14)
    at module.exports (/Applications/AMPPS/www/jump_start/wp-content/themes/jumpstart/node_modules/gulp/node_modules/orchestrator/lib/runTask.js:34:7)
    at Gulp.Orchestrator._runTask (/Applications/AMPPS/www/jump_start/wp-content/themes/jumpstart/node_modules/gulp/node_modules/orchestrator/index.js:273:3)
    at Gulp.Orchestrator._runStep (/Applications/AMPPS/www/jump_start/wp-content/themes/jumpstart/node_modules/gulp/node_modules/orchestrator/index.js:214:10)
    at Gulp.Orchestrator.start (/Applications/AMPPS/www/jump_start/wp-content/themes/jumpstart/node_modules/gulp/node_modules/orchestrator/index.js:134:8)
    at /usr/local/lib/node_modules/gulp/bin/gulp.js:129:20
    at process._tickCallback (node.js:419:13)

I don't really know what this error means. However, I have narrowed things down. It works If I comment out the following in my style.scss:

//@import "../bower_components/foundation/scss/foundation";

sindresorhus / gulp-autoprefixer

Autoprefixer with Foundation Framework issue #40