diff --git a/changelog/60_UNRELEASED_2020-xx-xx.md b/changelog/60_UNRELEASED_2020-xx-xx.md
index e3bfc992..ec86bcb9 100644
--- a/changelog/60_UNRELEASED_2020-xx-xx.md
+++ b/changelog/60_UNRELEASED_2020-xx-xx.md
@@ -199,6 +199,7 @@
 - New endpoints GET/POST/PUT `/users/{userId}/permissions` for the new user permissions feature mentioned above
 - The stock journal (entity `stock_log`) is now also available via the endpoint `/objects/{entity}` (=> `/objects/stock_log`)
 - Performance improvements of the `/stock/products/*` endpoints (thanks @fipwmaqzufheoxq92ebc)
+- The endpoint `/stock/products/{productId}/locations` now also has an optional query parameter `include_sub_products` to optionally also return locations of sub products of the given product
 - Fixed that the endpoint `/objects/{entity}/{objectId}` always returned successfully, even when the given object not exists (now returns `404` when the object is not found) (thanks @fipwmaqzufheoxq92ebc)
 - Fixed that the endpoint `/stock/volatile` didn't include products which expire today (thanks @fipwmaqzufheoxq92ebc)
 - Fixed that the endpoint `/objects/{entity}` did not include Userfields for Userentities (so the effective endpoint `/objects/userobjects`)
diff --git a/controllers/StockApiController.php b/controllers/StockApiController.php
index 7b1608d6..4ac52728 100644
--- a/controllers/StockApiController.php
+++ b/controllers/StockApiController.php
@@ -578,7 +578,6 @@ class StockApiController extends BaseApiController
 	public function ProductStockEntries(\Psr\Http\Message\ServerRequestInterface $request, \Psr\Http\Message\ResponseInterface $response, array $args)
 	{
 		$allowSubproductSubstitution = false;
-
 		if (isset($request->getQueryParams()['include_sub_products']) && filter_var($request->getQueryParams()['include_sub_products'], FILTER_VALIDATE_BOOLEAN))
 		{
 			$allowSubproductSubstitution = true;
@@ -589,7 +588,13 @@ class StockApiController extends BaseApiController
 
 	public function ProductStockLocations(\Psr\Http\Message\ServerRequestInterface $request, \Psr\Http\Message\ResponseInterface $response, array $args)
 	{
-		return $this->FilteredApiResponse($response, $this->getStockService()->GetProductStockLocations($args['productId']), $request->getQueryParams());
+		$allowSubproductSubstitution = false;
+		if (isset($request->getQueryParams()['include_sub_products']) && filter_var($request->getQueryParams()['include_sub_products'], FILTER_VALIDATE_BOOLEAN))
+		{
+			$allowSubproductSubstitution = true;
+		}
+
+		return $this->FilteredApiResponse($response, $this->getStockService()->GetProductStockLocations($args['productId'], $allowSubproductSubstitution), $request->getQueryParams());
 	}
 
 	public function RemoveProductFromShoppingList(\Psr\Http\Message\ServerRequestInterface $request, \Psr\Http\Message\ResponseInterface $response, array $args)
diff --git a/grocy.openapi.json b/grocy.openapi.json
index 53f97c4c..205a498a 100644
--- a/grocy.openapi.json
+++ b/grocy.openapi.json
@@ -1518,6 +1518,15 @@
 							"type": "integer"
 						}
 					},
+					{
+						"in": "query",
+						"name": "include_sub_products",
+						"required": false,
+						"description": "If sub product locations should be included (if the given product is a parent product and in addition to the ones of the given product)",
+						"schema": {
+							"type": "boolean"
+						}
+					},
 					{
 						"$ref": "#/components/parameters/query"
 					},
diff --git a/services/StockService.php b/services/StockService.php
index b400da0d..923f853d 100644
--- a/services/StockService.php
+++ b/services/StockService.php
@@ -662,27 +662,27 @@ class StockService extends BaseService
 
 	public function GetProductStockEntries($productId, $excludeOpened = false, $allowSubproductSubstitution = false, $ordered = true)
 	{
-		// In order of next use:
-		// First due first, then first in first out
-
 		$sqlWhereProductId = 'product_id = ' . $productId;
-
 		if ($allowSubproductSubstitution)
 		{
 			$sqlWhereProductId = 'product_id IN (SELECT sub_product_id FROM products_resolved WHERE parent_product_id = ' . $productId . ')';
 		}
 
 		$sqlWhereAndOpen = 'AND open IN (0, 1)';
-
 		if ($excludeOpened)
 		{
 			$sqlWhereAndOpen = 'AND open = 0';
 		}
+
 		$result = $this->getDatabase()->stock()->where($sqlWhereProductId . ' ' . $sqlWhereAndOpen);
+
+		// In order of next use:
+		// First due first, then first in first out
 		if ($ordered)
 		{
 			return $result->orderBy('best_before_date', 'ASC')->orderBy('purchased_date', 'ASC');
 		}
+
 		return $result;
 	}
 
@@ -692,9 +692,15 @@ class StockService extends BaseService
 		return FindAllObjectsInArrayByPropertyValue($stockEntries, 'location_id', $locationId);
 	}
 
-	public function GetProductStockLocations($productId)
+	public function GetProductStockLocations($productId, $allowSubproductSubstitution = false)
 	{
-		return $this->getDatabase()->stock_current_locations()->where('product_id', $productId);
+		$sqlWhereProductId = 'product_id = ' . $productId;
+		if ($allowSubproductSubstitution)
+		{
+			$sqlWhereProductId = 'product_id IN (SELECT sub_product_id FROM products_resolved WHERE parent_product_id = ' . $productId . ')';
+		}
+
+		return $this->getDatabase()->stock_current_locations()->where($sqlWhereProductId);
 	}
 
 	public function GetStockEntry($entryId)