diff --git a/include/aare/to_string.hpp b/include/aare/to_string.hpp
index 547ebc09..1ca3332e 100644
--- a/include/aare/to_string.hpp
+++ b/include/aare/to_string.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 
 /*
  *The file to_string.hpp contains conversion to and from string for various aare
diff --git a/python/src/bind_Cluster.hpp b/python/src/bind_Cluster.hpp
index 49618bf2..3e3e3c4f 100644
--- a/python/src/bind_Cluster.hpp
+++ b/python/src/bind_Cluster.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/Cluster.hpp"
 
 #include <cstdint>
diff --git a/python/src/bind_ClusterCollector.hpp b/python/src/bind_ClusterCollector.hpp
index fab91522..815ca7e2 100644
--- a/python/src/bind_ClusterCollector.hpp
+++ b/python/src/bind_ClusterCollector.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/ClusterCollector.hpp"
 #include "aare/ClusterFileSink.hpp"
 #include "aare/ClusterFinder.hpp"
diff --git a/python/src/bind_ClusterFile.hpp b/python/src/bind_ClusterFile.hpp
index 75c5458d..26af7813 100644
--- a/python/src/bind_ClusterFile.hpp
+++ b/python/src/bind_ClusterFile.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/CalculateEta.hpp"
 #include "aare/ClusterFile.hpp"
 #include "aare/defs.hpp"
diff --git a/python/src/bind_ClusterFileSink.hpp b/python/src/bind_ClusterFileSink.hpp
index 50600fcb..48820551 100644
--- a/python/src/bind_ClusterFileSink.hpp
+++ b/python/src/bind_ClusterFileSink.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/ClusterCollector.hpp"
 #include "aare/ClusterFileSink.hpp"
 #include "aare/ClusterFinder.hpp"
diff --git a/python/src/bind_ClusterFinder.hpp b/python/src/bind_ClusterFinder.hpp
index 8872db29..e312bcb2 100644
--- a/python/src/bind_ClusterFinder.hpp
+++ b/python/src/bind_ClusterFinder.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/ClusterCollector.hpp"
 #include "aare/ClusterFileSink.hpp"
 #include "aare/ClusterFinder.hpp"
diff --git a/python/src/bind_ClusterFinderMT.hpp b/python/src/bind_ClusterFinderMT.hpp
index 7e662841..d3a45962 100644
--- a/python/src/bind_ClusterFinderMT.hpp
+++ b/python/src/bind_ClusterFinderMT.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/ClusterCollector.hpp"
 #include "aare/ClusterFileSink.hpp"
 #include "aare/ClusterFinder.hpp"
diff --git a/python/src/bind_ClusterVector.hpp b/python/src/bind_ClusterVector.hpp
index 13ad5a6d..9b4b779b 100644
--- a/python/src/bind_ClusterVector.hpp
+++ b/python/src/bind_ClusterVector.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/ClusterCollector.hpp"
 #include "aare/ClusterFileSink.hpp"
 #include "aare/ClusterFinder.hpp"
diff --git a/python/src/bind_Defs.hpp b/python/src/bind_Defs.hpp
index e5f3cc3d..521d5529 100644
--- a/python/src/bind_Defs.hpp
+++ b/python/src/bind_Defs.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include <pybind11/operators.h>
 #include <pybind11/pybind11.h>
 #include <pybind11/stl.h>
diff --git a/python/src/bind_Eta.hpp b/python/src/bind_Eta.hpp
index e2b9302e..1f2dc32b 100644
--- a/python/src/bind_Eta.hpp
+++ b/python/src/bind_Eta.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/CalculateEta.hpp"
 #include "aare/to_string.hpp"
 
diff --git a/python/src/bind_FastPedestal.hpp b/python/src/bind_FastPedestal.hpp
index 5c278490..8bba55ea 100644
--- a/python/src/bind_FastPedestal.hpp
+++ b/python/src/bind_FastPedestal.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 
 #include "aare/FastPedestal.hpp"
 #include "np_helper.hpp"
diff --git a/python/src/bind_Interpolator.hpp b/python/src/bind_Interpolator.hpp
index 3b7a015b..de391f3b 100644
--- a/python/src/bind_Interpolator.hpp
+++ b/python/src/bind_Interpolator.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/CalculateEta.hpp"
 #include "aare/Interpolator.hpp"
 #include "aare/NDArray.hpp"
diff --git a/python/src/bind_Pedestal.hpp b/python/src/bind_Pedestal.hpp
index 9e8af455..02b4d32f 100644
--- a/python/src/bind_Pedestal.hpp
+++ b/python/src/bind_Pedestal.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 
 #include "aare/Pedestal.hpp"
 #include "np_helper.hpp"
diff --git a/python/src/bind_PedestalTrackingPixelHistogram.hpp b/python/src/bind_PedestalTrackingPixelHistogram.hpp
index 139b58a1..514ae263 100644
--- a/python/src/bind_PedestalTrackingPixelHistogram.hpp
+++ b/python/src/bind_PedestalTrackingPixelHistogram.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/hist/PedestalTrackingPixelHistogram.hpp"
 #include "np_helper.hpp"
 
diff --git a/python/src/bind_PixelHistogram.hpp b/python/src/bind_PixelHistogram.hpp
index d3a1b462..b0c97e35 100644
--- a/python/src/bind_PixelHistogram.hpp
+++ b/python/src/bind_PixelHistogram.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/hist/PixelHistogram.hpp"
 #include "np_helper.hpp"
 
diff --git a/python/src/bind_PixelMap.hpp b/python/src/bind_PixelMap.hpp
index 05d683e0..6aec76c3 100644
--- a/python/src/bind_PixelMap.hpp
+++ b/python/src/bind_PixelMap.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/PixelMap.hpp"
 #include "np_helper.hpp"
 
diff --git a/python/src/bind_RawFile.hpp b/python/src/bind_RawFile.hpp
index 11d1d31a..27e6511c 100644
--- a/python/src/bind_RawFile.hpp
+++ b/python/src/bind_RawFile.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/CtbRawFile.hpp"
 #include "aare/File.hpp"
 #include "aare/Frame.hpp"
diff --git a/python/src/bind_calibration.hpp b/python/src/bind_calibration.hpp
index cdb16b86..3cfc960e 100644
--- a/python/src/bind_calibration.hpp
+++ b/python/src/bind_calibration.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/calibration.hpp"
 
 #include <cstdint>
diff --git a/python/src/ctb_raw_file.hpp b/python/src/ctb_raw_file.hpp
index b6338bdd..1808c01d 100644
--- a/python/src/ctb_raw_file.hpp
+++ b/python/src/ctb_raw_file.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 
 #include "aare/CtbRawFile.hpp"
 #include "aare/File.hpp"
diff --git a/python/src/file.hpp b/python/src/file.hpp
index 030ba181..96960d91 100644
--- a/python/src/file.hpp
+++ b/python/src/file.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/CtbRawFile.hpp"
 #include "aare/File.hpp"
 #include "aare/Frame.hpp"
diff --git a/python/src/fit.hpp b/python/src/fit.hpp
index b41b1596..617cd6ea 100644
--- a/python/src/fit.hpp
+++ b/python/src/fit.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include <cstdint>
 #include <filesystem>
 #include <pybind11/pybind11.h>
diff --git a/python/src/jungfrau_data_file.hpp b/python/src/jungfrau_data_file.hpp
index 1ff4ff9d..84f4e6f4 100644
--- a/python/src/jungfrau_data_file.hpp
+++ b/python/src/jungfrau_data_file.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 
 #include "aare/JungfrauDataFile.hpp"
 #include "aare/defs.hpp"
diff --git a/python/src/raw_master_file.hpp b/python/src/raw_master_file.hpp
index d30762a4..5a0b049d 100644
--- a/python/src/raw_master_file.hpp
+++ b/python/src/raw_master_file.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 
 #include "aare/CtbRawFile.hpp"
 #include "aare/File.hpp"
diff --git a/python/src/raw_sub_file.hpp b/python/src/raw_sub_file.hpp
index da858058..66ec7d8b 100644
--- a/python/src/raw_sub_file.hpp
+++ b/python/src/raw_sub_file.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/CtbRawFile.hpp"
 #include "aare/File.hpp"
 #include "aare/Frame.hpp"
diff --git a/python/src/var_cluster.hpp b/python/src/var_cluster.hpp
index 1a3b674c..9734f406 100644
--- a/python/src/var_cluster.hpp
+++ b/python/src/var_cluster.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include "aare/VarClusterFinder.hpp"
 #include "np_helper.hpp"
 
diff --git a/tests/friend_test.hpp b/tests/friend_test.hpp
index 2f2a4f3e..b06795d2 100644
--- a/tests/friend_test.hpp
+++ b/tests/friend_test.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #define FRIEND_TEST(test_name) friend void test_name##_impl();
 
 #define TEST_CASE_PRIVATE_FWD(test_name)                                       \
diff --git a/tests/test_macros.hpp b/tests/test_macros.hpp
index f6cc7dfd..4f4cab3d 100644
--- a/tests/test_macros.hpp
+++ b/tests/test_macros.hpp
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
+#pragma once
 #include <catch2/catch_test_macros.hpp>
 
 #include <catch2/interfaces/catch_interfaces_capture.hpp>