diff --git a/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete.tsx b/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete.tsx
index 54762931e..047e3c096 100644
--- a/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete.tsx
+++ b/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete.tsx
@@ -51,10 +51,13 @@ export function Autocomplete(props: {
   })
 
   function insertPart(text: string, part: PromptInfo["parts"][number]) {
-    const append = "@" + text + " "
     const input = props.input()
     const currentCursorOffset = input.visualCursor.offset
 
+    const charAfterCursor = props.value.at(currentCursorOffset)
+    const needsSpace = charAfterCursor !== " " && charAfterCursor !== undefined
+    const append = "@" + text + (needsSpace ? " " : "")
+
     input.cursorOffset = store.index
     const startCursor = input.logicalCursor
     input.cursorOffset = currentCursorOffset
@@ -316,8 +319,9 @@ export function Autocomplete(props: {
         }
         if (!store.visible) {
           if (e.name === "@") {
-            const last = props.value.at(-1)
-            if (last === " " || last === undefined) {
+            const cursorOffset = props.input().visualCursor.offset
+            const charBeforeCursor = cursorOffset === 0 ? undefined : props.value.at(cursorOffset - 1)
+            if (charBeforeCursor === " " || charBeforeCursor === undefined) {
               show("@")
             }
           }