diff --git a/src/fvm.hpp b/src/fvm.hpp
index 644dd48b27f347a53b93f44cef14612cd81605f6..1dbbdfdec87d3051d30450182c6349614701e31e 100644
--- a/src/fvm.hpp
+++ b/src/fvm.hpp
@@ -4,6 +4,7 @@
 #include <map>
 #include <string>
 #include <vector>
+#include <Vector.hpp>
 
 #include "algorithms.hpp"
 #include "cell.hpp"
@@ -16,8 +17,6 @@
 #include "stimulus.hpp"
 #include "util.hpp"
 
-#include <Vector.hpp>
-
 namespace nest {
 namespace mc {
 namespace fvm {
diff --git a/src/mechanism.hpp b/src/mechanism.hpp
index 5a4873663def934dfd252e89330306b6d21c36b2..7a06a7330e06bb14000e7c262c3db55fe4dc7135 100644
--- a/src/mechanism.hpp
+++ b/src/mechanism.hpp
@@ -1,7 +1,5 @@
 #pragma once
 
-#pragma once
-
 #include <memory>
 #include <string>
 
diff --git a/tests/test_algorithms.cpp b/tests/test_algorithms.cpp
index 7ecfa894ca3760efb5be5db95e2be85b97e759db..584bdf8ad10db170b44604d3db8f8047d3c29860 100644
--- a/tests/test_algorithms.cpp
+++ b/tests/test_algorithms.cpp
@@ -5,7 +5,6 @@
 
 #include "../src/algorithms.hpp"
 
-
 TEST(algorithms, sum)
 {
     // sum of 10 times 2 is 20
diff --git a/tests/test_matrix.cpp b/tests/test_matrix.cpp
index 2f2587f44ecce48e4e2222795695b78a8b70705e..f74b47985649101a5bd4c79c07a911ed65b85c8b 100644
--- a/tests/test_matrix.cpp
+++ b/tests/test_matrix.cpp
@@ -3,9 +3,8 @@
 
 #include "gtest.h"
 
-#include "../src/matrix.hpp"
 #include "../src/math.hpp"
-
+#include "../src/matrix.hpp"
 
 TEST(matrix, construct_from_parent_only)
 {
diff --git a/tests/test_segment.cpp b/tests/test_segment.cpp
index 9c3df625db9ef87110474d35a5ce88f3f4e07f09..490f0e5ece7b8956de830029bf1188c4f912b7c6 100644
--- a/tests/test_segment.cpp
+++ b/tests/test_segment.cpp
@@ -4,7 +4,6 @@
 
 #include "../src/segment.hpp"
 
-
 TEST(segments, soma)
 {
     using namespace nest::mc;
diff --git a/tests/test_tree.cpp b/tests/test_tree.cpp
index 334a90cb5357e10d101b9b123e76bd6c9f0622af..3db9adbb77ae65607935239ff52a7b97402a0253 100644
--- a/tests/test_tree.cpp
+++ b/tests/test_tree.cpp
@@ -8,7 +8,6 @@
 
 #include "../src/cell_tree.hpp"
 
-
 using json = nlohmann::json;
 using range = memory::Range;
 
diff --git a/tests/validate_ball_and_stick.cpp b/tests/validate_ball_and_stick.cpp
index 2b85502201b26a903a6f22d02dd9fa68cfd97145..f871610cf002b4a4c058b4c8394beb2e2bae2b04 100644
--- a/tests/validate_ball_and_stick.cpp
+++ b/tests/validate_ball_and_stick.cpp
@@ -4,7 +4,6 @@
 #include "gtest.h"
 #include "util.hpp"
 
-
 #include "../src/cell.hpp"
 #include "../src/fvm.hpp"
 
diff --git a/tests/validate_soma.cpp b/tests/validate_soma.cpp
index 7b5c4c9b138e0f2cfc5a3c1153361f5e842fe96f..df9ac7bd5811875948edc7ccf56d0bb60ed5d7b8 100644
--- a/tests/validate_soma.cpp
+++ b/tests/validate_soma.cpp
@@ -1,15 +1,12 @@
 #include <fstream>
 #include <json.hpp>
 
-
 #include "gtest.h"
 #include "util.hpp"
 
 #include "../src/cell.hpp"
 #include "../src/fvm.hpp"
 
-
-
 // compares results with those generated by nrn/soma.py
 // single compartment model with HH channels
 TEST(soma, neuron_baseline)