diff --git a/make/build.mk b/make/build.mk
index 741656ab9cab679e89c4557f8257d5f5aadb4cb6..a18416a76fc766919f77bf0ac0baaf3fb94b054f 100644
--- a/make/build.mk
+++ b/make/build.mk
@@ -2,9 +2,9 @@
 
 .PHONY: build-images
 build-images: ## Build Docker images.
-	docker build --platform=$PLATFORM --network=host -t dbrepo-core:build --target build ./lib/java/dbrepo-core
-	docker build --platform=$PLATFORM --network=host -t dbrepo-data-service:build --target build dbrepo-data-service
-	docker build --platform=$PLATFORM --network=host -t dbrepo-metadata-service:build --target build dbrepo-metadata-service
+	docker build --platform=$(PLATFORM) --network=host -t dbrepo-core:build --target build ./lib/java/dbrepo-core
+	docker build --platform=$(PLATFORM) --network=host -t dbrepo-data-service:build --target build dbrepo-data-service
+	docker build --platform=$(PLATFORM) --network=host -t dbrepo-metadata-service:build --target build dbrepo-metadata-service
 	docker compose build --parallel
 
 .PHONY: build-data-service