diff --git a/__tests__/ExpensiMark-HTML-test.js b/__tests__/ExpensiMark-HTML-test.js
index 2d7be7ca..17f235c5 100644
--- a/__tests__/ExpensiMark-HTML-test.js
+++ b/__tests__/ExpensiMark-HTML-test.js
@@ -1542,6 +1542,13 @@ describe('edit mode', () => {
         expect(parser.replace(quoteTestStartString, {shouldKeepWhitespace: true})).toBe(quoteTestReplacedString);
     });
 
+    test('nested quote and heading with many spaces after #', () => {
+        const quoteTestStartString = '>#    Hello world';
+        const quoteTestReplacedString = '<blockquote><h1>   Hello world</h1></blockquote>';
+
+        expect(parser.replace(quoteTestStartString, {shouldKeepWhitespace: true})).toBe(quoteTestReplacedString);
+    });
+
     describe('trailing whitespace', () => {
         test('nothing', () => {
             const quoteTestStartString = '>Hello world!';
diff --git a/lib/ExpensiMark.js b/lib/ExpensiMark.js
index ea496fe2..894ec385 100644
--- a/lib/ExpensiMark.js
+++ b/lib/ExpensiMark.js
@@ -74,7 +74,12 @@ export default class ExpensiMark {
 
             {
                 name: 'heading1',
-                regex: /^# +(?! )((?:(?!<pre>|\n|\r\n).)+)/gm,
+                process: (textToProcess, replacement, shouldKeepWhitespace = false) => {
+                    if (shouldKeepWhitespace) {
+                        return textToProcess.replace(/^# ( *(?! )(?:(?!<pre>|\n|\r\n).)+)/gm, replacement);
+                    }
+                    return textToProcess.replace(/^# +(?! )((?:(?!<pre>|\n|\r\n).)+)/gm, replacement);
+                },
                 replacement: '<h1>$1</h1>',
             },
 
@@ -200,11 +205,11 @@ export default class ExpensiMark {
                         /^&gt; *(?! )(?![^<]*(?:<\/pre>|<\/code>))([^\v\n\r]+)/gm,
                     );
                     if (shouldKeepWhitespace) {
-                        return textToProcess.replace(regex, replacement);
+                        return textToProcess.replace(regex, g1 => replacement(g1, shouldKeepWhitespace));
                     }
                     return this.modifyTextForQuote(regex, textToProcess, replacement);
                 },
-                replacement: (g1) => {
+                replacement: (g1, shouldKeepWhitespace = false) => {
                     // We want to enable 2 options of nested heading inside the blockquote: "># heading" and "> # heading".
                     // To do this we need to parse body of the quote without first space
                     let isStartingWithSpace = false;
@@ -212,7 +217,7 @@ export default class ExpensiMark {
                         isStartingWithSpace = !!g2;
                         return '';
                     });
-                    const replacedText = this.replace(textToReplace, {filterRules: ['heading1'], shouldEscapeText: false});
+                    const replacedText = this.replace(textToReplace, {filterRules: ['heading1'], shouldEscapeText: false, shouldKeepWhitespace});
                     return `<blockquote>${isStartingWithSpace ? ' ' : ''}${replacedText}</blockquote>`;
                 },
             },