diff --git a/src/api/index.ts b/src/api/index.ts
index 5daa53396f..520b3205c7 100644
--- a/src/api/index.ts
+++ b/src/api/index.ts
@@ -64,7 +64,7 @@ export interface ApiHandler {
 	countTokens(content: Array<Anthropic.Messages.ContentBlockParam>): Promise<number>
 }
 
-export function buildApiHandler(configuration: ProviderSettings): ApiHandler {
+export function buildApiHandler(configuration: ProviderSettings): ApiHandler & Partial<SingleCompletionHandler> {
 	const { apiProvider, ...options } = configuration
 
 	switch (apiProvider) {
diff --git a/src/utils/single-completion-handler.ts b/src/utils/single-completion-handler.ts
index 4606a17bab..b00559bc4b 100644
--- a/src/utils/single-completion-handler.ts
+++ b/src/utils/single-completion-handler.ts
@@ -17,9 +17,9 @@ export async function singleCompletionHandler(apiConfiguration: ProviderSettings
 	const handler = buildApiHandler(apiConfiguration)
 
 	// Check if handler supports single completions
-	if (!("completePrompt" in handler)) {
+	if (!handler.completePrompt) {
 		throw new Error("The selected API provider does not support prompt enhancement")
 	}
 
-	return (handler as SingleCompletionHandler).completePrompt(promptText)
+	return handler.completePrompt(promptText)
 }