diff --git a/packages/opencode/src/cli/cmd/tui/component/vim/vim-handler.ts b/packages/opencode/src/cli/cmd/tui/component/vim/vim-handler.ts
index 2eb0ec7e4ed8..35933d6e58b7 100644
--- a/packages/opencode/src/cli/cmd/tui/component/vim/vim-handler.ts
+++ b/packages/opencode/src/cli/cmd/tui/component/vim/vim-handler.ts
@@ -120,6 +120,7 @@ export function createVimHandler(input: {
 
   function value(event: VimEvent) {
     if (event.name === "space") return " "
+    if (event.shift && event.name?.length === 1 && /[a-z]/.test(event.name)) return event.name.toUpperCase()
     return event.name ?? ""
   }
 
diff --git a/packages/opencode/test/cli/tui/vim-motions.test.ts b/packages/opencode/test/cli/tui/vim-motions.test.ts
index a32be49d36bf..7b074bee3c9f 100644
--- a/packages/opencode/test/cli/tui/vim-motions.test.ts
+++ b/packages/opencode/test/cli/tui/vim-motions.test.ts
@@ -1611,6 +1611,17 @@ describe("vim motion handler", () => {
     expect(ctx.state.mode()).toBe("replace")
   })
 
+  test("replace mode preserves shifted uppercase letters", () => {
+    const ctx = createHandler("abcd", { mode: "replace" })
+    ctx.textarea.cursorOffset = 1
+
+    const key = createEvent("x", { shift: true })
+    expect(ctx.handler.handleKey(key.event)).toBe(true)
+    expect(key.prevented()).toBe(true)
+    expect(ctx.textarea.plainText).toBe("aXcd")
+    expect(ctx.textarea.cursorOffset).toBe(2)
+  })
+
   test("replace mode overwrites with space key", () => {
     const ctx = createHandler("abcd", { mode: "replace" })
     ctx.textarea.cursorOffset = 1