diff --git a/test/test_minimization/test_minimizers.py b/test/test_minimization/test_minimizers.py
index fb5f67c863fdf37e3a076627460983917a871370..42ef0258717c2f40085f0e2a6031a5b8c96dc7c1 100644
--- a/test/test_minimization/test_minimizers.py
+++ b/test/test_minimization/test_minimizers.py
@@ -1,3 +1,21 @@
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Copyright(C) 2013-2017 Max-Planck-Society
+#
+# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
+# and financially supported by the Studienstiftung des deutschen Volkes.
+
 import unittest
 import numpy as np
 from numpy.testing import assert_allclose
diff --git a/test/test_operators/test_adjoint.py b/test/test_operators/test_adjoint.py
index 0a0c4b278e789d4ee3a39f686ac469468e1b4196..6c87609ba01717aa8422f81ec7d8a82e1d1cb46f 100644
--- a/test/test_operators/test_adjoint.py
+++ b/test/test_operators/test_adjoint.py
@@ -1,3 +1,21 @@
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Copyright(C) 2013-2017 Max-Planck-Society
+#
+# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
+# and financially supported by the Studienstiftung des deutschen Volkes.
+
 import unittest
 import nifty2go as ift
 import numpy as np
diff --git a/test/test_operators/test_composed_operator.py b/test/test_operators/test_composed_operator.py
index 1a4890879c9809c83062616794cd5906ab6201df..e5f1c2231b660b78489f0e20216c749dfc1435d9 100644
--- a/test/test_operators/test_composed_operator.py
+++ b/test/test_operators/test_composed_operator.py
@@ -1,3 +1,21 @@
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Copyright(C) 2013-2018 Max-Planck-Society
+#
+# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
+# and financially supported by the Studienstiftung des deutschen Volkes.
+
 import unittest
 from numpy.testing import assert_allclose, assert_equal
 import nifty2go as ift
diff --git a/test/test_operators/test_diagonal_operator.py b/test/test_operators/test_diagonal_operator.py
index a5ddaea7c439d0ed939f2014d9b8318f5ebc9604..bd9072d59128218997496657364161689fadff99 100644
--- a/test/test_operators/test_diagonal_operator.py
+++ b/test/test_operators/test_diagonal_operator.py
@@ -1,3 +1,21 @@
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Copyright(C) 2013-2017 Max-Planck-Society
+#
+# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
+# and financially supported by the Studienstiftung des deutschen Volkes.
+
 from __future__ import division
 import unittest
 from numpy.testing import assert_equal, assert_allclose
diff --git a/test/test_operators/test_fft_operator.py b/test/test_operators/test_fft_operator.py
index 1c6f55a3bbdd45b5c727b83c9129f90e9e109537..69a917529a1601f06e68d8308f52e8ef3108fb94 100644
--- a/test/test_operators/test_fft_operator.py
+++ b/test/test_operators/test_fft_operator.py
@@ -11,7 +11,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
-# Copyright(C) 2013-2017 Max-Planck-Society
+# Copyright(C) 2013-2018 Max-Planck-Society
 #
 # NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
 # and financially supported by the Studienstiftung des deutschen Volkes.
diff --git a/test/test_operators/test_response_operator.py b/test/test_operators/test_response_operator.py
index 3d25e822209f83d0fe2a92bf1d9eb63faee43c7a..3961c8ec4c732dd6ea30c081ea524da7a9151477 100644
--- a/test/test_operators/test_response_operator.py
+++ b/test/test_operators/test_response_operator.py
@@ -1,3 +1,21 @@
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Copyright(C) 2013-2017 Max-Planck-Society
+#
+# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
+# and financially supported by the Studienstiftung des deutschen Volkes.
+
 import unittest
 from numpy.testing import assert_allclose
 import nifty2go as ift