diff --git a/packages/cli/src/run.ts b/packages/cli/src/run.ts
index 6a98e15d4e..2f2c86552f 100644
--- a/packages/cli/src/run.ts
+++ b/packages/cli/src/run.ts
@@ -189,8 +189,10 @@ export async function runScript(
             partialCb: (args) => {
                 const { responseChunk, tokensSoFar } = args
                 tokens = tokensSoFar
-                if (stream && responseChunk) process.stdout.write(responseChunk)
-                else if (!isQuiet) process.stderr.write(responseChunk)
+                if (responseChunk !== undefined) {
+                    if (stream) process.stdout.write(responseChunk)
+                    else if (!isQuiet) process.stderr.write(responseChunk)
+                }
                 partialCb?.(args)
             },
             skipLLM,