diff --git a/README.md b/README.md
index 3becbddd..392ceeda 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,9 @@ const prediction = await replicate
     "stability-ai/stable-diffusion:db21e45d3f7023abc2a46ee38a23973f6dce16bb082a930b0c49861f96d1e5bf"
   )
   .predict({
-    prompt: "an astronaut riding on a horse",
+    input: {
+      prompt: "an astronaut riding on a horse",
+    },
   });
 
 console.log(prediction.output);
@@ -45,7 +47,9 @@ await replicate
   )
   .predict(
     {
-      prompt: "an astronaut riding on a horse",
+      input: {
+        prompt: "an astronaut riding on a horse",
+      },
     },
     {
       onUpdate: (prediction) => {
@@ -66,7 +70,9 @@ const prediction = await replicate
     "stability-ai/stable-diffusion:db21e45d3f7023abc2a46ee38a23973f6dce16bb082a930b0c49861f96d1e5bf"
   )
   .createPrediction({
-    prompt: "an astronaut riding on a horse",
+    input: {
+      prompt: "an astronaut riding on a horse",
+    },
   });
 
 console.log(prediction.status); // "starting"
@@ -89,7 +95,9 @@ await replicate
   )
   .createPrediction(
     {
-      prompt: "an astronaut riding on a horse",
+      input: {
+        prompt: "an astronaut riding on a horse",
+      },
     },
     {
       // See https://replicate.com/docs/reference/http#create-prediction--webhook
diff --git a/lib/Model.js b/lib/Model.js
index ed27db36..1c0bcec5 100644
--- a/lib/Model.js
+++ b/lib/Model.js
@@ -47,7 +47,7 @@ export default class Model extends ReplicateObject {
   }
 
   async predict(
-    input,
+    { input },
     {
       onUpdate = noop,
       onTemporaryError = noop,
@@ -122,12 +122,16 @@ export default class Model extends ReplicateObject {
     return prediction;
   }
 
-  async createPrediction(input, { webhook, webhookEventsFilter } = {}) {
+  async createPrediction({ input }, { webhook, webhookEventsFilter } = {}) {
     // This is here and not on `Prediction` because conceptually, a prediction
     // from a model "belongs" to the model. It's an odd feature of the API that
     // the prediction creation isn't an action on the model (or that it doesn't
     // actually use the model information, only the version), but we don't need
     // to expose that to users of this library.
+    if (!input) {
+      throw new ReplicateError("input is required");
+    }
+
     const predictionData = await this.client.request("POST /v1/predictions", {
       version: this.version,
       input,
diff --git a/lib/Model.test.js b/lib/Model.test.js
index 057bd75e..a21c0060 100644
--- a/lib/Model.test.js
+++ b/lib/Model.test.js
@@ -86,7 +86,7 @@ describe("predict()", () => {
     );
 
     await model.predict(
-      { text: "test text" },
+      { input: { text: "test text" } },
       {},
       { defaultPollingInterval: 0 }
     );
@@ -128,7 +128,7 @@ describe("predict()", () => {
       .mockImplementation((action) => requestMockReturnValues[action]);
 
     await model.predict(
-      { text: "test text" },
+      { input: { text: "test text" } },
       {},
       { defaultPollingInterval: 0 }
     );
@@ -182,7 +182,7 @@ describe("predict()", () => {
     });
 
     const prediction = await model.predict(
-      { text: "test text" },
+      { input: { text: "test text" } },
       {},
       { defaultPollingInterval: 0 }
     );
@@ -237,7 +237,7 @@ describe("predict()", () => {
     const backoffFn = jest.fn(() => 0);
 
     const prediction = await model.predict(
-      { text: "test text" },
+      { input: { text: "test text" } },
       {},
       { defaultPollingInterval: 0, backoffFn }
     );
@@ -255,7 +255,7 @@ describe("createPrediction()", () => {
       status: PredictionStatus.SUCCEEDED,
     });
 
-    await model.createPrediction({ text: "test text" });
+    await model.createPrediction({ input: { text: "test text" } });
 
     expect(client.request).toHaveBeenCalledWith("POST /v1/predictions", {
       version: "testversion",
@@ -270,7 +270,7 @@ describe("createPrediction()", () => {
     });
 
     await model.createPrediction(
-      { text: "test text" },
+      { input: { text: "test text" } },
       { webhook: "http://test.host/webhook" }
     );
 
@@ -288,7 +288,7 @@ describe("createPrediction()", () => {
     });
 
     await model.createPrediction(
-      { text: "test text" },
+      { input: { text: "test text" } },
       {
         webhook: "http://test.host/webhook",
         webhookEventsFilter: ["output", "completed"],