diff --git a/extensions/op-blocknote-hocuspocus/package.json b/extensions/op-blocknote-hocuspocus/package.json
index eb6c394f33a..59469de1047 100644
--- a/extensions/op-blocknote-hocuspocus/package.json
+++ b/extensions/op-blocknote-hocuspocus/package.json
@@ -23,14 +23,14 @@
     "node": ">=22.18"
   },
   "dependencies": {
-    "@blocknote/server-util": "^0.44.2",
+    "@blocknote/server-util": "^0.51.0",
     "@hocuspocus/extension-logger": "^3.4.4",
     "@hocuspocus/server": "^3.4.0",
-    "op-blocknote-extensions": "https://github.com/opf/op-blocknote-extensions/releases/download/v0.0.18/op-blocknote-extensions-0.0.18.tgz",
+    "op-blocknote-extensions": "https://github.com/opf/op-blocknote-extensions/releases/download/v0.1.0/op-blocknote-extensions-0.1.0.tgz",
     "tsx": "^4.21.0"
   },
   "devDependencies": {
-    "@blocknote/core": "^0.44.2",
+    "@blocknote/core": "^0.51.0",
     "@eslint/js": "^9.35.0",
     "@eslint/json": "^1.2.0",
     "@stylistic/eslint-plugin": "^5.3.1",
diff --git a/extensions/op-blocknote-hocuspocus/src/extensions/openProjectApi.ts b/extensions/op-blocknote-hocuspocus/src/extensions/openProjectApi.ts
index ef107e22f82..f7fb851ee14 100644
--- a/extensions/op-blocknote-hocuspocus/src/extensions/openProjectApi.ts
+++ b/extensions/op-blocknote-hocuspocus/src/extensions/openProjectApi.ts
@@ -2,7 +2,10 @@ import { BlockNoteSchema } from "@blocknote/core";
 import { ServerBlockNoteEditor } from "@blocknote/server-util";
 import type { beforeHandleMessagePayload, onAuthenticatePayload, onLoadDocumentPayload, onStoreDocumentPayload, onTokenSyncPayload } from "@hocuspocus/server";
 import { Extension } from "@hocuspocus/server";
-import { openProjectWorkPackageStaticBlockSpec } from "op-blocknote-extensions";
+import {
+  openProjectWorkPackageStaticBlockSpec,
+  openProjectWorkPackageStaticInlineSpec,
+} from "op-blocknote-extensions/server";
 import * as Y from "yjs";
 import { TokenExpired, TokenExpiryMissing, unauthorized } from "../closeEvents";
 import { decryptAndValidateToken } from "../services/tokenValidationService";
@@ -11,7 +14,10 @@ import { fetchResource } from "../services/resourceService";
 
 export const editorSchema = BlockNoteSchema.create().extend({
   blockSpecs: {
-    "openProjectWorkPackage": openProjectWorkPackageStaticBlockSpec(),
+    openProjectWorkPackageBlock: openProjectWorkPackageStaticBlockSpec(),
+  },
+  inlineContentSpecs: {
+    openProjectWorkPackageInline: openProjectWorkPackageStaticInlineSpec,
   },
 });
 
diff --git a/frontend/package.json b/frontend/package.json
index a10eae73392..6d5840f63c5 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -75,9 +75,9 @@
     "@appsignal/javascript": "^1.6.1",
     "@appsignal/plugin-breadcrumbs-console": "^1.1.37",
     "@appsignal/plugin-breadcrumbs-network": "^1.1.24",
-    "@blocknote/core": "^0.44.2",
-    "@blocknote/mantine": "^0.44.2",
-    "@blocknote/react": "^0.44.2",
+    "@blocknote/core": "^0.51.0",
+    "@blocknote/mantine": "^0.51.0",
+    "@blocknote/react": "^0.51.0",
     "@braintree/sanitize-url": "^7.1.1",
     "@datorama/akita": "^8.0.1",
     "@floating-ui/dom": "^1.2.1",
@@ -158,7 +158,7 @@
     "ng2-dragula": "^6.0.0",
     "ngx-cookie-service": "^21.1.0",
     "observable-array": "0.0.4",
-    "op-blocknote-extensions": "https://github.com/opf/op-blocknote-extensions/releases/download/v0.0.26/op-blocknote-extensions-0.0.26.tgz",
+    "op-blocknote-extensions": "https://github.com/opf/op-blocknote-extensions/releases/download/v0.1.0/op-blocknote-extensions-0.1.0.tgz",
     "openapi-explorer": "^2.4.793",
     "pako": "^2.0.3",
     "qr-creator": "^1.0.0",
diff --git a/frontend/src/react/components/OpBlockNoteEditor.tsx b/frontend/src/react/components/OpBlockNoteEditor.tsx
index 420745b4caf..bced2de6eed 100644
--- a/frontend/src/react/components/OpBlockNoteEditor.tsx
+++ b/frontend/src/react/components/OpBlockNoteEditor.tsx
@@ -96,22 +96,24 @@ export function OpBlockNoteEditor({
   }, [openProjectUrl, localeString]);
 
   const editorParams = useMemo<Partial<BlockNoteEditorOptions<typeof schema.blockSchema, typeof schema.inlineContentSchema, typeof schema.styleSchema>>>(() => {
-    const baseCollaboration = {
-      fragment: doc.getXmlFragment('document-store'),
-      user: {
-        name: activeUser.username,
-        color: hocuspocusProvider ? generateRandomColor() : '#333333',
-        ...(hocuspocusProvider && { id: activeUser.id }),
-      } as unknown as CollaborativeUser,
-    };
-
     return {
       schema,
-      collaboration: {
-        ...baseCollaboration,
-        provider: hocuspocusProvider ?? null,
-        ...(hocuspocusProvider && { showCursorLabels: 'activity' as const }),
-      },
+      // BlockNote 0.51 tightened `collaboration.provider` to a non-null shape
+      // and `awareness: Awareness | undefined` (vs Hocuspocus's
+      // `Awareness | null`). Omit the whole `collaboration` block when no
+      // provider is wired up; cast the provider at the boundary otherwise.
+      ...(hocuspocusProvider && {
+        collaboration: {
+          fragment: doc.getXmlFragment('document-store'),
+          user: {
+            name: activeUser.username,
+            color: generateRandomColor(),
+            id: activeUser.id,
+          } as unknown as CollaborativeUser,
+          provider: hocuspocusProvider as unknown as { awareness?:NonNullable<HocuspocusProvider['awareness']> },
+          showCursorLabels: 'activity' as const,
+        },
+      }),
       dictionary: localeDictionary,
       ...(attachmentsEnabled && { uploadFile }),
       // When external link capture is enabled, intercept clicks on external