diff --git a/milli/src/vector/openai.rs b/milli/src/vector/openai.rs
index 8712c7894..9deb2e2da 100644
--- a/milli/src/vector/openai.rs
+++ b/milli/src/vector/openai.rs
@@ -271,11 +271,7 @@ impl Embedder {
         let request = OpenAiRequest {
             model: self.options.embedding_model.name(),
             input: texts,
-            dimension: if self.options.embedding_model.supports_overriding_dimensions() {
-                self.options.dimensions.as_ref()
-            } else {
-                None
-            },
+            dimensions: self.overriden_dimensions(),
         };
         let response = client
             .post(OPENAI_EMBEDDINGS_URL)
@@ -360,8 +356,11 @@ impl Embedder {
         tokens: &[usize],
         client: &reqwest::Client,
     ) -> Result<Embedding, Retry> {
-        let request =
-            OpenAiTokensRequest { model: self.options.embedding_model.name(), input: tokens };
+        let request = OpenAiTokensRequest {
+            model: self.options.embedding_model.name(),
+            input: tokens,
+            dimensions: self.overriden_dimensions(),
+        };
         let response = client
             .post(OPENAI_EMBEDDINGS_URL)
             .json(&request)
@@ -414,6 +413,14 @@ impl Embedder {
     pub fn distribution(&self) -> Option<DistributionShift> {
         self.options.embedding_model.distribution()
     }
+
+    fn overriden_dimensions(&self) -> Option<usize> {
+        if self.options.embedding_model.supports_overriding_dimensions() {
+            self.options.dimensions
+        } else {
+            None
+        }
+    }
 }
 
 // retrying in case of failure
@@ -473,13 +480,16 @@ impl Retry {
 struct OpenAiRequest<'a, S: AsRef<str> + serde::Serialize> {
     model: &'a str,
     input: &'a [S],
-    dimension: Option<&'a usize>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    dimensions: Option<usize>,
 }
 
 #[derive(Debug, Serialize)]
 struct OpenAiTokensRequest<'a> {
     model: &'a str,
     input: &'a [usize],
+    #[serde(skip_serializing_if = "Option::is_none")]
+    dimensions: Option<usize>,
 }
 
 #[derive(Debug, Deserialize)]