diff --git a/src/build.extension.ts b/src/build.extension.ts
index 0c6cc56..16d61f7 100644
--- a/src/build.extension.ts
+++ b/src/build.extension.ts
@@ -59,6 +59,7 @@ export function BuildTypes({ logger, hass, type_build, config, internal }: TServ
         `  AppleNotificationData,`,
         `  NotificationData,`,
         `  PICK_ENTITY,`,
+        `  WeatherGetForecasts,`,
         `} from "./helpers";`,
         ``,
         PICK_FROM_PLATFORM,
diff --git a/src/i-call-service.extension.ts b/src/i-call-service.extension.ts
index c2dc12e..dfc907a 100644
--- a/src/i-call-service.extension.ts
+++ b/src/i-call-service.extension.ts
@@ -1,6 +1,6 @@
 import { DOWN, is, TServiceParams, UP } from "@digital-alchemy/core";
 import { HassServiceDTO, ServiceListField, ServiceListServiceTarget } from "@digital-alchemy/hass";
-import { factory, SyntaxKind, TypeElement } from "typescript";
+import { factory, SyntaxKind, TypeElement, TypeNode, TypeParameterDeclaration } from "typescript";
 
 export async function ICallServiceExtension({ hass, type_build }: TServiceParams) {
   return async function () {
@@ -49,16 +49,49 @@ export async function ICallServiceExtension({ hass, type_build }: TServiceParams
       // >     [service_name]: (service_data) => Promise<void | unknown>
       // >   }
       // > }
+      const isReturnResponse = is.boolean(value.response?.optional);
+      const genericIdent = "T";
+
+      // Override default return type for some known cases
+      let defaultReturnType: TypeNode = factory.createKeywordTypeNode(SyntaxKind.UnknownKeyword);
+      if (domain === "weather" && key === "get_forecasts") {
+        defaultReturnType = factory.createTypeReferenceNode(
+          factory.createIdentifier("WeatherGetForecasts"),
+          undefined,
+        );
+      }
+
+      // Set up for the default case of (service_data) => Promise<void>
+      let generic: TypeParameterDeclaration[] | undefined = undefined;
+      let returnType: TypeNode | undefined = factory.createTypeReferenceNode(
+        factory.createIdentifier("Promise"),
+        [factory.createKeywordTypeNode(SyntaxKind.VoidKeyword)],
+      );
+
+      // If the service might return a response, change instead to <T = unknown>(service_data) => Promise<T>
+      if (isReturnResponse) {
+        generic = [
+          factory.createTypeParameterDeclaration(
+            undefined,
+            factory.createIdentifier(genericIdent),
+            undefined,
+            defaultReturnType,
+          ),
+        ];
+        returnType = factory.createExpressionWithTypeArguments(
+          factory.createIdentifier("Promise"),
+          [factory.createTypeReferenceNode(factory.createIdentifier(genericIdent), undefined)],
+        );
+      }
+
       return type_build.tsdoc.serviceComment(
         factory.createMethodSignature(
           undefined,
           factory.createIdentifier(key),
           undefined,
-          undefined,
+          generic,
           serviceParameters(domain, key, value),
-          factory.createTypeReferenceNode(factory.createIdentifier("Promise"), [
-            factory.createKeywordTypeNode(SyntaxKind.VoidKeyword),
-          ]),
+          returnType,
         ),
         key,
         value,