diff --git a/components/Blocks/TextBlock/index.tsx b/components/Blocks/TextBlock/index.tsx
index 4fe6db4f..71574e9a 100644
--- a/components/Blocks/TextBlock/index.tsx
+++ b/components/Blocks/TextBlock/index.tsx
@@ -34,12 +34,14 @@ const HeadingStyle = {
   1: "font-bold [font-family:var(--theme-heading-font)]",
   2: "font-bold [font-family:var(--theme-heading-font)]",
   3: "font-bold text-secondary [font-family:var(--theme-heading-font)]",
+  4: "font-bold text-secondary [font-family:var(--theme-heading-font)]",
 } as { [level: number]: string };
 
 const headingFontSize = {
   1: blockTextSize.h1,
   2: blockTextSize.h2,
   3: blockTextSize.h3,
+  4: blockTextSize.h4,
 } as { [level: number]: string };
 
 export function TextBlock(
diff --git a/components/Blocks/TextBlock/inputRules.ts b/components/Blocks/TextBlock/inputRules.ts
index 9dbbd8c6..90673c91 100644
--- a/components/Blocks/TextBlock/inputRules.ts
+++ b/components/Blocks/TextBlock/inputRules.ts
@@ -210,7 +210,7 @@ export const inputrules = (
       }),
 
       //Header
-      new InputRule(/^([#]{1,3})\s$/, (state, match) => {
+      new InputRule(/^([#]{1,4})\s$/, (state, match) => {
         let tr = state.tr;
         tr.delete(0, match[0].length);
         let headingLevel = match[1].length;
diff --git a/components/Blocks/TextBlock/useHandlePaste.ts b/components/Blocks/TextBlock/useHandlePaste.ts
index f3bad456..5a4e021a 100644
--- a/components/Blocks/TextBlock/useHandlePaste.ts
+++ b/components/Blocks/TextBlock/useHandlePaste.ts
@@ -244,6 +244,11 @@ const createBlockFromHTML = (
       type = "heading";
       break;
     }
+    case "H4": {
+      headingLevel = 4;
+      type = "heading";
+      break;
+    }
     case "DIV": {
       type = "card";
       break;