diff --git a/src/modules/alt.ts b/src/modules/alt.ts
index fe7c284..a168d59 100644
--- a/src/modules/alt.ts
+++ b/src/modules/alt.ts
@@ -10,11 +10,11 @@ import { calculateCost } from "../utils/calculateCost.js";
 import { isSubscribed } from "../utils/isSubscribed.js";
 import { logger } from "../utils/logger.js";
 import { replyToError } from "../utils/replyToError.js";
-import type { ImageBlockParam } from "@anthropic-ai/sdk/resources/index.js";
+import type { Base64ImageSource } from "@anthropic-ai/sdk/resources/index.js";
 
 const isValidContentType = (
   type: string,
-): type is ImageBlockParam["source"]["media_type"] => {
+): type is Base64ImageSource["media_type"] => {
   return [
     "image/jpg",
     "image/jpeg",
@@ -100,7 +100,7 @@ export const alt = async(
           role: "user",
         },
       ],
-      model:       "claude-3-5-sonnet-latest",
+      model:       "claude-sonnet-4-20250514",
       system:      `${personality} Your role in this conversation is to generate descriptive and accessible alt-text for the user's image. Be as descriptive as possible. Do not include ANYTHING in your response EXCEPT the actual alt-text. Wrap the text in a multi-line code block for easy copying.`,
       temperature: 1,
     });
diff --git a/src/modules/evaluate.ts b/src/modules/evaluate.ts
index b59c502..4df8a5f 100644
--- a/src/modules/evaluate.ts
+++ b/src/modules/evaluate.ts
@@ -31,7 +31,7 @@ export const evaluate = async(
     // eslint-disable-next-line @typescript-eslint/naming-convention -- Required key format for SDK.
       max_tokens:  2000,
       messages:    [ { content: code, role: "user" } ],
-      model:       "claude-3-5-sonnet-latest",
+      model:       "claude-sonnet-4-20250514",
       system:      `${personality} Your role in this conversation is to evaluate the user's code and provide the result. Wrap ONLY THE CODE RESULT in a multi-line code block for easy copying.`,
       temperature: 1,
     });
diff --git a/src/modules/mood.ts b/src/modules/mood.ts
index c8f4a3d..8ee768d 100644
--- a/src/modules/mood.ts
+++ b/src/modules/mood.ts
@@ -32,7 +32,7 @@ export const mood = async(
     // eslint-disable-next-line @typescript-eslint/naming-convention -- Required key format for SDK.
       max_tokens:  2000,
       messages:    [ { content: prompt, role: "user" } ],
-      model:       "claude-3-5-sonnet-latest",
+      model:       "claude-sonnet-4-20250514",
       system:      `${personality} Your role in this conversation is to analyse the text the user provides for the overall sentiment and mood of the author.`,
       temperature: 1,
     });
diff --git a/src/modules/proofread.ts b/src/modules/proofread.ts
index f8092b4..7155945 100644
--- a/src/modules/proofread.ts
+++ b/src/modules/proofread.ts
@@ -32,7 +32,7 @@ export const proofread = async(
     // eslint-disable-next-line @typescript-eslint/naming-convention -- Required key format for SDK.
       max_tokens:  2000,
       messages:    [ { content: prompt, role: "user" } ],
-      model:       "claude-3-5-sonnet-latest",
+      model:       "claude-sonnet-4-20250514",
       system:      `${personality} Your role in this conversation is to proofread the text the user has provided. You should identify spelling and grammatical errors using British English.`,
       temperature: 1,
     });
diff --git a/src/modules/query.ts b/src/modules/query.ts
index 93d36e5..79d2d58 100644
--- a/src/modules/query.ts
+++ b/src/modules/query.ts
@@ -32,7 +32,7 @@ export const query = async(
     // eslint-disable-next-line @typescript-eslint/naming-convention -- Required key format for SDK.
       max_tokens:  2000,
       messages:    [ { content: prompt, role: "user" } ],
-      model:       "claude-3-5-sonnet-latest",
+      model:       "claude-sonnet-4-20250514",
       system:      `${personality} Your role in this conversation is to answer the user's question to the best of your abilities. When possible, include links to relevant sources.`,
       temperature: 1,
     });
diff --git a/src/modules/summarise.ts b/src/modules/summarise.ts
index 082779e..4c1f8cf 100644
--- a/src/modules/summarise.ts
+++ b/src/modules/summarise.ts
@@ -32,7 +32,7 @@ export const summarise = async(
     // eslint-disable-next-line @typescript-eslint/naming-convention -- Required key format for SDK.
       max_tokens:  2000,
       messages:    [ { content: prompt, role: "user" } ],
-      model:       "claude-3-5-sonnet-latest",
+      model:       "claude-sonnet-4-20250514",
       system:      `${personality} Your role in this conversation is to summarise the text the user has provided. Your goal is to reach 250 words or less. Wrap ONLY THE SUMMARY in multi-line code block so it is easy to copy.`,
       temperature: 1,
     });