diff --git a/packages/core/src/api/blockManipulation/__snapshots__/blockManipulation.test.ts.snap b/packages/core/src/api/blockManipulation/__snapshots__/blockManipulation.test.ts.snap
index 9a49952d7a..ecc3057eda 100644
--- a/packages/core/src/api/blockManipulation/__snapshots__/blockManipulation.test.ts.snap
+++ b/packages/core/src/api/blockManipulation/__snapshots__/blockManipulation.test.ts.snap
@@ -712,3 +712,210 @@ Line2",
   },
 ]
 `;
+
+exports[`Update block cases > Update children only 1`] = `
+[
+  {
+    "children": [
+      {
+        "children": [],
+        "content": [
+          {
+            "styles": {},
+            "text": "Heading",
+            "type": "text",
+          },
+        ],
+        "id": "3",
+        "props": {
+          "backgroundColor": "default",
+          "level": 1,
+          "textAlignment": "left",
+          "textColor": "default",
+        },
+        "type": "heading",
+      },
+    ],
+    "content": [
+      {
+        "styles": {},
+        "text": "Paragraph",
+        "type": "text",
+      },
+    ],
+    "id": "1",
+    "props": {
+      "backgroundColor": "default",
+      "textAlignment": "left",
+      "textColor": "default",
+    },
+    "type": "paragraph",
+  },
+  {
+    "children": [],
+    "content": [],
+    "id": "0",
+    "props": {
+      "backgroundColor": "default",
+      "textAlignment": "left",
+      "textColor": "default",
+    },
+    "type": "paragraph",
+  },
+]
+`;
+
+exports[`Update block cases > Update content and children 1`] = `
+[
+  {
+    "children": [
+      {
+        "children": [],
+        "content": [
+          {
+            "styles": {},
+            "text": "Heading",
+            "type": "text",
+          },
+        ],
+        "id": "3",
+        "props": {
+          "backgroundColor": "default",
+          "level": 1,
+          "textAlignment": "left",
+          "textColor": "default",
+        },
+        "type": "heading",
+      },
+    ],
+    "content": [
+      {
+        "styles": {},
+        "text": "Updated Paragraph",
+        "type": "text",
+      },
+    ],
+    "id": "1",
+    "props": {
+      "backgroundColor": "default",
+      "textAlignment": "left",
+      "textColor": "default",
+    },
+    "type": "paragraph",
+  },
+  {
+    "children": [],
+    "content": [],
+    "id": "0",
+    "props": {
+      "backgroundColor": "default",
+      "textAlignment": "left",
+      "textColor": "default",
+    },
+    "type": "paragraph",
+  },
+]
+`;
+
+exports[`Update block cases > Update content only 1`] = `
+[
+  {
+    "children": [
+      {
+        "children": [],
+        "content": [
+          {
+            "styles": {},
+            "text": "Nested Paragraph",
+            "type": "text",
+          },
+        ],
+        "id": "2",
+        "props": {
+          "backgroundColor": "default",
+          "textAlignment": "left",
+          "textColor": "default",
+        },
+        "type": "paragraph",
+      },
+    ],
+    "content": [
+      {
+        "styles": {},
+        "text": "Updated Paragraph",
+        "type": "text",
+      },
+    ],
+    "id": "1",
+    "props": {
+      "backgroundColor": "default",
+      "textAlignment": "left",
+      "textColor": "default",
+    },
+    "type": "paragraph",
+  },
+  {
+    "children": [],
+    "content": [],
+    "id": "0",
+    "props": {
+      "backgroundColor": "default",
+      "textAlignment": "left",
+      "textColor": "default",
+    },
+    "type": "paragraph",
+  },
+]
+`;
+
+exports[`Update block cases > Update type only 1`] = `
+[
+  {
+    "children": [
+      {
+        "children": [],
+        "content": [
+          {
+            "styles": {},
+            "text": "Nested Paragraph",
+            "type": "text",
+          },
+        ],
+        "id": "2",
+        "props": {
+          "backgroundColor": "default",
+          "textAlignment": "left",
+          "textColor": "default",
+        },
+        "type": "paragraph",
+      },
+    ],
+    "content": [
+      {
+        "styles": {},
+        "text": "Paragraph",
+        "type": "text",
+      },
+    ],
+    "id": "1",
+    "props": {
+      "backgroundColor": "default",
+      "level": 1,
+      "textAlignment": "left",
+      "textColor": "default",
+    },
+    "type": "heading",
+  },
+  {
+    "children": [],
+    "content": [],
+    "id": "0",
+    "props": {
+      "backgroundColor": "default",
+      "textAlignment": "left",
+      "textColor": "default",
+    },
+    "type": "paragraph",
+  },
+]
+`;
diff --git a/packages/core/src/api/blockManipulation/blockManipulation.test.ts b/packages/core/src/api/blockManipulation/blockManipulation.test.ts
index 6bef807c80..58bd244a85 100644
--- a/packages/core/src/api/blockManipulation/blockManipulation.test.ts
+++ b/packages/core/src/api/blockManipulation/blockManipulation.test.ts
@@ -56,6 +56,12 @@ let singleBlock: PartialBlock<
   DefaultStyleSchema
 >;
 
+let singleBlockWithChildren: PartialBlock<
+  typeof schema.blockSchema,
+  DefaultInlineContentSchema,
+  DefaultStyleSchema
+>;
+
 let multipleBlocks: PartialBlock<
   typeof schema.blockSchema,
   DefaultInlineContentSchema,
@@ -88,6 +94,17 @@ beforeEach(() => {
     content: "Paragraph",
   };
 
+  singleBlockWithChildren = {
+    type: "paragraph",
+    content: "Paragraph",
+    children: [
+      {
+        type: "paragraph",
+        content: "Nested Paragraph",
+      },
+    ],
+  };
+
   multipleBlocks = [
     {
       type: "heading",
@@ -285,6 +302,75 @@ describe("Insert, Update, & Delete Blocks", () => {
   });
 });
 
+describe("Update block cases", () => {
+  it("Update type only", async () => {
+    await waitForEditor();
+
+    const existingBlock = editor.document[0];
+    editor.insertBlocks([singleBlockWithChildren], existingBlock);
+
+    const newBlock = editor.document[0];
+    editor.updateBlock(newBlock, {
+      type: "heading",
+    });
+
+    expect(editor.document).toMatchSnapshot();
+  });
+
+  it("Update content only", async () => {
+    await waitForEditor();
+
+    const existingBlock = editor.document[0];
+    editor.insertBlocks([singleBlockWithChildren], existingBlock);
+
+    const newBlock = editor.document[0];
+    editor.updateBlock(newBlock, {
+      content: "Updated Paragraph",
+    });
+
+    expect(editor.document).toMatchSnapshot();
+  });
+
+  it("Update children only", async () => {
+    await waitForEditor();
+
+    const existingBlock = editor.document[0];
+    editor.insertBlocks([singleBlockWithChildren], existingBlock);
+
+    const newBlock = editor.document[0];
+    editor.updateBlock(newBlock, {
+      children: [
+        {
+          type: "heading",
+          content: "Heading",
+        },
+      ],
+    });
+
+    expect(editor.document).toMatchSnapshot();
+  });
+
+  it("Update content and children", async () => {
+    await waitForEditor();
+
+    const existingBlock = editor.document[0];
+    editor.insertBlocks([singleBlockWithChildren], existingBlock);
+
+    const newBlock = editor.document[0];
+    editor.updateBlock(newBlock, {
+      content: "Updated Paragraph",
+      children: [
+        {
+          type: "heading",
+          content: "Heading",
+        },
+      ],
+    });
+
+    expect(editor.document).toMatchSnapshot();
+  });
+});
+
 describe("Update Line Breaks", () => {
   it("Update paragraph with line break", async () => {
     await waitForEditor();
diff --git a/packages/core/src/pm-nodes/BlockContainer.ts b/packages/core/src/pm-nodes/BlockContainer.ts
index aa476f2ea5..6ead8b3ded 100644
--- a/packages/core/src/pm-nodes/BlockContainer.ts
+++ b/packages/core/src/pm-nodes/BlockContainer.ts
@@ -286,7 +286,7 @@ export const BlockContainer = Node.create<{
               state.tr
                 .replaceWith(
                   startPos,
-                  endPos,
+                  startPos + contentNode.nodeSize,
                   state.schema.nodes[newType].create(
                     {
                       ...contentNode.attrs,