diff --git a/packages/editor/src/behaviors/behavior.core.insert.ts b/packages/editor/src/behaviors/behavior.core.insert.ts
index 862fe70bd..389cf0426 100644
--- a/packages/editor/src/behaviors/behavior.core.insert.ts
+++ b/packages/editor/src/behaviors/behavior.core.insert.ts
@@ -1,8 +1,9 @@
+import {isSpan} from '@portabletext/schema'
 import {getActiveAnnotationsMarks} from '../selectors/selector.get-active-annotation-marks'
 import {getActiveDecorators} from '../selectors/selector.get-active-decorators'
 import {getFocusSpan} from '../selectors/selector.get-focus-span'
-import {getMarkState} from '../selectors/selector.get-mark-state'
-import {raise} from './behavior.types.action'
+import {getFocusTextBlock} from '../selectors/selector.get-focus-text-block'
+import {forward, raise} from './behavior.types.action'
 import {defineBehavior} from './behavior.types.behavior'
 
 export const coreInsertBehaviors = [
@@ -15,38 +16,113 @@ export const coreInsertBehaviors = [
         return false
       }
 
-      const markState = getMarkState(snapshot)
       const activeDecorators = getActiveDecorators(snapshot)
       const activeAnnotations = getActiveAnnotationsMarks(snapshot)
+      const activeMarks = [...activeDecorators, ...activeAnnotations]
+      const focusMarks = focusSpan.node.marks ?? []
 
-      if (markState && markState.state === 'unchanged') {
-        const markStateDecorators = (markState.marks ?? []).filter((mark) =>
-          snapshot.context.schema.decorators
-            .map((decorator) => decorator.name)
-            .includes(mark),
-        )
-
-        if (
-          markStateDecorators.length === activeDecorators.length &&
-          markStateDecorators.every((mark) => activeDecorators.includes(mark))
-        ) {
-          return false
+      if (
+        activeMarks.length === focusMarks.length &&
+        activeMarks.every((mark) => focusMarks.includes(mark))
+      ) {
+        return false
+      }
+
+      const selection = snapshot.context.selection
+
+      if (selection) {
+        const offset = selection.focus.offset
+        const atStart = offset === 0
+        const atEnd = offset === focusSpan.node.text.length
+
+        const focusBlock = getFocusTextBlock(snapshot)
+
+        if (focusBlock) {
+          const children = focusBlock.node.children
+          const focusIndex = children.findIndex(
+            (child) => child._key === focusSpan.node._key,
+          )
+
+          if (atEnd && focusIndex < children.length - 1) {
+            const nextChild = children[focusIndex + 1]
+
+            if (nextChild && isSpan(snapshot.context, nextChild)) {
+              const nextMarks = nextChild.marks ?? []
+
+              if (
+                activeMarks.length === nextMarks.length &&
+                activeMarks.every((mark) => nextMarks.includes(mark))
+              ) {
+                return {
+                  type: 'move' as const,
+                  targetSpanKey: nextChild._key,
+                  targetOffset: 0,
+                }
+              }
+            }
+          }
+
+          if (atStart && focusIndex > 0) {
+            const prevChild = children[focusIndex - 1]
+
+            if (prevChild && isSpan(snapshot.context, prevChild)) {
+              const prevMarks = prevChild.marks ?? []
+
+              if (
+                activeMarks.length === prevMarks.length &&
+                activeMarks.every((mark) => prevMarks.includes(mark))
+              ) {
+                return {
+                  type: 'move' as const,
+                  targetSpanKey: prevChild._key,
+                  targetOffset: prevChild.text.length,
+                }
+              }
+            }
+          }
         }
       }
 
-      return {activeDecorators, activeAnnotations}
+      return {type: 'insert' as const, activeDecorators, activeAnnotations}
     },
     actions: [
-      ({snapshot, event}, {activeDecorators, activeAnnotations}) => [
-        raise({
-          type: 'insert.child',
-          child: {
-            _type: snapshot.context.schema.span.name,
-            text: event.text,
-            marks: [...activeDecorators, ...activeAnnotations],
-          },
-        }),
-      ],
+      ({snapshot, event}, guardResponse) => {
+        if (guardResponse.type === 'move') {
+          const {targetSpanKey, targetOffset} = guardResponse
+          const blockPath = snapshot.context.selection!.focus.path.slice(0, 1)
+
+          return [
+            raise({
+              type: 'select',
+              at: {
+                anchor: {
+                  path: [...blockPath, 'children', {_key: targetSpanKey}],
+                  offset: targetOffset,
+                },
+                focus: {
+                  path: [...blockPath, 'children', {_key: targetSpanKey}],
+                  offset: targetOffset,
+                },
+                backward: false,
+              },
+            }),
+            forward(event),
+          ]
+        }
+
+        const {activeDecorators, activeAnnotations} = guardResponse
+
+        return [
+          raise({
+            type: 'insert.child',
+            child: {
+              _type: snapshot.context.schema.span.name,
+              text: event.text,
+              marks: [...activeDecorators, ...activeAnnotations],
+            },
+          }),
+        ]
+      },
     ],
   }),
 ]
diff --git a/packages/editor/tests/stable-keys.test.tsx b/packages/editor/tests/stable-keys.test.tsx
new file mode 100644
index 000000000..7a5ef3b61
--- /dev/null
+++ b/packages/editor/tests/stable-keys.test.tsx
@@ -0,0 +1,83 @@
+import {createTestKeyGenerator} from '@portabletext/test'
+import {describe, expect, test, vi} from 'vitest'
+import {userEvent} from 'vitest/browser'
+import {defineSchema} from '../src'
+import {createTestEditor} from '../src/test/vitest'
+
+describe('Feature: Stable keys', () => {
+  test('Scenario: Typing after annotation', async () => {
+    const keyGenerator = createTestKeyGenerator()
+    const blockKey = keyGenerator()
+    const fooKey = keyGenerator()
+    const barKey = keyGenerator()
+    const bazKey = keyGenerator()
+    const linkKey = keyGenerator()
+
+    const {editor, locator} = await createTestEditor({
+      keyGenerator,
+      schemaDefinition: defineSchema({
+        annotations: [{name: 'link'}],
+      }),
+      initialValue: [
+        {
+          _type: 'block',
+          _key: blockKey,
+          children: [
+            {_type: 'span', _key: fooKey, text: 'foo ', marks: []},
+            {_type: 'span', _key: barKey, text: 'bar', marks: [linkKey]},
+            {_type: 'span', _key: bazKey, text: ' baz', marks: []},
+          ],
+          markDefs: [
+            {_type: 'link', _key: linkKey, href: 'https://portabletext.org'},
+          ],
+          style: 'normal',
+        },
+      ],
+    })
+
+    // When the editor is focused
+    await userEvent.click(locator)
+
+    // And the caret is put before " baz"
+    const beforeBazSelection = {
+      anchor: {
+        path: [{_key: blockKey}, 'children', {_key: bazKey}],
+        offset: 0,
+      },
+      focus: {
+        path: [{_key: blockKey}, 'children', {_key: bazKey}],
+        offset: 0,
+      },
+      backward: false,
+    }
+    editor.send({
+      type: 'select',
+      at: beforeBazSelection,
+    })
+    await vi.waitFor(() => {
+      expect(editor.getSnapshot().context.selection).toEqual(beforeBazSelection)
+    })
+
+    // And "new" is typed
+    await userEvent.keyboard('new')
+
+    // Then the text is "foo ,bar,new baz"
+    await vi.waitFor(() => {
+      expect(editor.getSnapshot().context.value).toEqual([
+        {
+          _type: 'block',
+          _key: blockKey,
+          children: [
+            {_type: 'span', _key: fooKey, text: 'foo ', marks: []},
+            {_type: 'span', _key: barKey, text: 'bar', marks: [linkKey]},
+            {_type: 'span', _key: bazKey, text: 'new baz', marks: []},
+          ],
+          markDefs: [
+            {_type: 'link', _key: linkKey, href: 'https://portabletext.org'},
+          ],
+          style: 'normal',
+        },
+      ])
+    })
+  })
+})