diff --git a/packages/opencode/src/session/prompt.ts b/packages/opencode/src/session/prompt.ts
index d036c6542d..2981b50b54 100644
--- a/packages/opencode/src/session/prompt.ts
+++ b/packages/opencode/src/session/prompt.ts
@@ -1558,6 +1558,7 @@ export const layer = Layer.effect(
       }
 
       const templateParts = yield* resolvePromptParts(template)
+      const inputFiles = new Set(input.parts?.map((part) => new URL(part.url).pathname))
       const isSubtask = (agent.mode === "subagent" && cmd.subtask !== false) || cmd.subtask === true
       const parts = isSubtask
         ? [
@@ -1570,7 +1571,10 @@ export const layer = Layer.effect(
               prompt: templateParts.find((y) => y.type === "text")?.text ?? "",
             },
           ]
-        : [...templateParts, ...(input.parts ?? [])]
+        : [
+            ...templateParts.filter((part) => part.type !== "file" || !inputFiles.has(new URL(part.url).pathname)),
+            ...(input.parts ?? []),
+          ]
 
       const userAgent = isSubtask ? (input.agent ?? (yield* agents.defaultInfo()).name) : agent.name
       const userModel = isSubtask