diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7a5a882..64c8f96 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -62,7 +62,7 @@ jobs:
           cmake  -DBUILD_PYTHON:BOOL=ON -DBUILD_SHARED_LIBS:BOOL=ON  -Dndicapi_BUILD_APPLICATIONS:BOOL=OFF ..
           make
           cd ..
-	  python -m build
+          python -m build
 
       - name: build ubuntu manylinux
         if: matrix.os == 'ubuntu-latest'