diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 35874aba54c545f714a7ec1bab7d69d97363b22f..90d7e1c1bd0146bfb71e487c4b370c5480c9c040 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -4,7 +4,7 @@ image: "derq3k/card10-build-env:20190806-195837Z-f95b541-dirty"
 build:
     stage: build
     script:
-        - ./bootstrap.sh
+        - ./bootstrap.sh --werror
         - ninja -C build/
         - arm-none-eabi-size build/bootloader/bootloader.elf build/epicardium/epicardium.elf build/pycardium/pycardium.elf
     only:
@@ -14,7 +14,7 @@ build:
 release:
     stage: build
     script:
-        - ./bootstrap.sh
+        - ./bootstrap.sh --werror
         - ninja -C build/
         - arm-none-eabi-size build/bootloader/bootloader.elf build/epicardium/epicardium.elf build/pycardium/pycardium.elf
     only: