diff --git a/CMakeLists.txt b/CMakeLists.txt
index a1bdfb4b62..5db9dc443a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1369,7 +1369,7 @@ if(openPMD_BUILD_TESTING)
                             --infile ../samples/git-sample/thetaMode/data%T.h5     \
                             --outfile ../samples/git-sample/thetaMode/data.bp &&   \
                                                                                    \
-                        ${Python_EXECUTABLE}                                       \
+                        ${MPI_TEST_EXE} ${Python_EXECUTABLE}                       \
                             ${openPMD_RUNTIME_OUTPUT_DIRECTORY}/openpmd-pipe       \
                             --infile ../samples/git-sample/thetaMode/data.bp       \
                             --outfile ../samples/git-sample/thetaMode/data%T.json  \