diff --git a/codex-rs/codex-api/src/endpoint/images.rs b/codex-rs/codex-api/src/endpoint/images.rs
index 47226e4ecf..9d1bd41eea 100644
--- a/codex-rs/codex-api/src/endpoint/images.rs
+++ b/codex-rs/codex-api/src/endpoint/images.rs
@@ -245,7 +245,7 @@ mod tests {
                     }],
                     prompt: "add a red hat".to_string(),
                     background: None,
-                    model: Some("gpt-image-1.5".to_string()),
+                    model: "gpt-image-1.5".to_string(),
                     n: None,
                     quality: None,
                     size: None,
diff --git a/codex-rs/codex-api/src/images.rs b/codex-rs/codex-api/src/images.rs
index 1824c8ea76..f915a5f78d 100644
--- a/codex-rs/codex-api/src/images.rs
+++ b/codex-rs/codex-api/src/images.rs
@@ -21,8 +21,7 @@ pub struct ImageEditRequest {
     pub prompt: String,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub background: Option<ImageBackground>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub model: Option<String>,
+    pub model: String,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub n: Option<u64>,
     #[serde(skip_serializing_if = "Option::is_none")]