diff --git a/.gitignore b/.gitignore
index c155967..35a04f3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 /node_modules
 /lib
 mergely-*.tgz
+package-lock.json
diff --git a/CHANGES.md b/CHANGES.md
index 3a85d78..2927ae1 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,5 +1,17 @@
 # Changes
 
+## 4.0.6
+
+* #89: fixes missing merge buttons
+
+## 4.0.5
+
+* #85: fixes XSS vulnerability with DOM id
+
+## 4.0.2
+
+* #83: fixes poor rendering performance
+
 ## 4.0.0
 
 ### Breaking changes
diff --git a/src/mergely.js b/src/mergely.js
index 2f93090..bb9d00f 100644
--- a/src/mergely.js
+++ b/src/mergely.js
@@ -461,11 +461,11 @@ jQuery.extend(Mgly.CodeMirrorDiffView.prototype, {
 			lineNumbers: this.settings.line_numbers
 		};
 		var lhs_gutters = [];
-		if (this.lhs_cmsettings.line_numbers) {
+		if (this.lhs_cmsettings.lineNumbers) {
 			lhs_gutters = ['merge', 'CodeMirror-linenumbers']
 		}
 		var rhs_gutters = [];
-		if (this.rhs_cmsettings.line_numbers) {
+		if (this.rhs_cmsettings.lineNumbers) {
 			rhs_gutters = ['merge', 'CodeMirror-linenumbers']
 		}
 		jQuery.extend(true, this.lhs_cmsettings, this.settings.cmsettings, { gutters: lhs_gutters }, this.settings);
@@ -683,7 +683,7 @@ jQuery.extend(Mgly.CodeMirrorDiffView.prototype, {
 		}
 		else {
 			// homebrew
-			var style = 'opacity:0.4;width:10px;height:15px;background-color:#888;cursor:pointer;text-align:center;color:#eee;border:1px solid #222;margin-right:5px;margin-top: -2px;';
+			var style = 'opacity:0.6;height:16px;background-color:#bfbfbf;cursor:pointer;text-align:center;color:#eee;border:1px solid #848484;margin-right:5px;margin-top:-2px;';
 			merge_lhs_button = '<div style="' + style + '" title="Merge left">&lt;</div>';
 			merge_rhs_button = '<div style="' + style + '" title="Merge right">&gt;</div>';
 		}
diff --git a/tests/mergely.spec.js b/tests/mergely.spec.js
index 55b4c65..557292d 100644
--- a/tests/mergely.spec.js
+++ b/tests/mergely.spec.js
@@ -402,6 +402,7 @@ describe('mergely', function () {
 						for (let i = 0; i < opt.next; ++i) {
 							$('#mergely').mergely('scrollToDiff', 'next');
 						}
+						expect($('.merge-button').length > 0).to.be.true;
 						$('#mergely').mergely('mergeCurrentChange', opt.dir);
 						if (opt.dir === 'lhs') {
 							expect($('#mergely').mergely('get', 'lhs')).to.equal(opt.expect || opt.rhs);