diff --git a/shared/naturalcrit/markdown.js b/shared/naturalcrit/markdown.js
index 45d573262..6ceee2b03 100644
--- a/shared/naturalcrit/markdown.js
+++ b/shared/naturalcrit/markdown.js
@@ -415,9 +415,9 @@ const nonbreakingSpaces = {
 const definitionListsSingleLine = {
 	name  : 'definitionListsSingleLine',
 	level : 'block',
-	start(src) { return src.match(/\n[^\n]*?::[^\n]*/m)?.index; },  // Hint to Marked.js to stop and check for a match
+	start(src) { return src.match(/\n[^\n]*?::[^:\n]*/m)?.index; },  // Hint to Marked.js to stop and check for a match
 	tokenizer(src, tokens) {
-		const regex = /^([^\n]*?)::([^\n]*)(?:\n|$)/ym;
+		const regex = /^([^\n]*?)::([^\:\>][^\n]*)(?:\n|$)/ym;
 		let match;
 		let endIndex = 0;
 		const definitions = [];
diff --git a/tests/markdown/horizontalSpaces.test.js b/tests/markdown/horizontalSpaces.test.js
new file mode 100644
index 000000000..6789b934c
--- /dev/null
+++ b/tests/markdown/horizontalSpaces.test.js
@@ -0,0 +1,49 @@
+/* eslint-disable max-lines */
+
+import Markdown from 'naturalcrit/markdown.js';
+
+describe('Hard Breaks', ()=>{
+	test('Single Break', function() {
+		const source = ':>\n\n';
+		const rendered = Markdown.render(source).trim();
+		expect(rendered, `Input:\n${source}`, { showPrefix: false }).toBe(`<p>&nbsp;\n</p>`);
+	});
+
+	test('Double Break', function() {
+		const source = ':>>\n\n';
+		const rendered = Markdown.render(source).trim();
+		expect(rendered, `Input:\n${source}`, { showPrefix: false }).toBe(`<p>&nbsp;&nbsp;\n</p>`);
+	});
+
+	test('Triple Break', function() {
+		const source = ':>>>\n\n';
+		const rendered = Markdown.render(source).trim();
+		expect(rendered, `Input:\n${source}`, { showPrefix: false }).toBe(`<p>&nbsp;&nbsp;&nbsp;\n</p>`);
+	});
+
+	test('Many Break', function() {
+		const source = ':>>>>>>>>>>\n\n';
+		const rendered = Markdown.render(source).trim();
+		expect(rendered, `Input:\n${source}`, { showPrefix: false }).toBe(`<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;\n</p>`);
+	});
+
+	test('Multiple sets of Breaks', function() {
+		const source = ':>>>\n:>>>\n:>>>';
+		const rendered = Markdown.render(source).trim();
+		expect(rendered, `Input:\n${source}`, { showPrefix: false }).toBe(`<p>&nbsp;&nbsp;&nbsp;\n\n&nbsp;&nbsp;&nbsp;\n\n&nbsp;&nbsp;&nbsp;\n</p>`);
+	});
+
+	test('Break directly between two paragraphs', function() {
+		const source = 'Line 1\n:>>\nLine 2';
+		const rendered = Markdown.render(source).trim();
+		expect(rendered, `Input:\n${source}`, { showPrefix: false }).toBe(`<p>Line 1\n&nbsp;&nbsp;\n\nLine 2</p>`);
+	});
+
+	test('Ignored inside a code block', function() {
+		const source = '```\n\n:>\n\n```\n';
+		const rendered = Markdown.render(source).trim();
+		expect(rendered, `Input:\n${source}`, { showPrefix: false }).toBe(`<pre><code>\n:&gt;\n</code></pre>`);
+	});
+
+});
+