diff --git a/examples/domain-adaptation/plot_otda_color_images.py b/examples/domain-adaptation/plot_otda_color_images.py
index 929365ed2..d70f1fc42 100644
--- a/examples/domain-adaptation/plot_otda_color_images.py
+++ b/examples/domain-adaptation/plot_otda_color_images.py
@@ -27,9 +27,9 @@
 r = np.random.RandomState(42)
 
 
-def im2mat(I):
+def im2mat(img):
     """Converts an image to matrix (one pixel per line)"""
-    return I.reshape((I.shape[0] * I.shape[1], I.shape[2]))
+    return img.reshape((img.shape[0] * img.shape[1], img.shape[2]))
 
 
 def mat2im(X, shape):
@@ -37,8 +37,8 @@ def mat2im(X, shape):
     return X.reshape(shape)
 
 
-def minmax(I):
-    return np.clip(I, 0, 1)
+def minmax(img):
+    return np.clip(img, 0, 1)
 
 
 ##############################################################################
diff --git a/examples/domain-adaptation/plot_otda_linear_mapping.py b/examples/domain-adaptation/plot_otda_linear_mapping.py
index dbf16b8f4..be475107c 100644
--- a/examples/domain-adaptation/plot_otda_linear_mapping.py
+++ b/examples/domain-adaptation/plot_otda_linear_mapping.py
@@ -79,9 +79,9 @@
 # ---------------
 
 
-def im2mat(I):
+def im2mat(img):
     """Converts and image to matrix (one pixel per line)"""
-    return I.reshape((I.shape[0] * I.shape[1], I.shape[2]))
+    return img.reshape((img.shape[0] * img.shape[1], img.shape[2]))
 
 
 def mat2im(X, shape):
@@ -89,8 +89,8 @@ def mat2im(X, shape):
     return X.reshape(shape)
 
 
-def minmax(I):
-    return np.clip(I, 0, 1)
+def minmax(img):
+    return np.clip(img, 0, 1)
 
 
 # Loading images
diff --git a/examples/domain-adaptation/plot_otda_mapping_colors_images.py b/examples/domain-adaptation/plot_otda_mapping_colors_images.py
index ee5c8b0f8..aa41d22a3 100644
--- a/examples/domain-adaptation/plot_otda_mapping_colors_images.py
+++ b/examples/domain-adaptation/plot_otda_mapping_colors_images.py
@@ -29,9 +29,9 @@
 r = np.random.RandomState(42)
 
 
-def im2mat(I):
+def im2mat(img):
     """Converts and image to matrix (one pixel per line)"""
-    return I.reshape((I.shape[0] * I.shape[1], I.shape[2]))
+    return img.reshape((img.shape[0] * img.shape[1], img.shape[2]))
 
 
 def mat2im(X, shape):
@@ -39,8 +39,8 @@ def mat2im(X, shape):
     return X.reshape(shape)
 
 
-def minmax(I):
-    return np.clip(I, 0, 1)
+def minmax(img):
+    return np.clip(img, 0, 1)
 
 
 ##############################################################################
diff --git a/examples/gromov/plot_gromov_barycenter.py b/examples/gromov/plot_gromov_barycenter.py
index f6f031a74..e2d88baf3 100755
--- a/examples/gromov/plot_gromov_barycenter.py
+++ b/examples/gromov/plot_gromov_barycenter.py
@@ -84,9 +84,9 @@ def smacof_mds(C, dim, max_iter=3000, eps=1e-9):
 # The four distributions are constructed from 4 simple images
 
 
-def im2mat(I):
+def im2mat(img):
     """Converts and image to matrix (one pixel per line)"""
-    return I.reshape((I.shape[0] * I.shape[1], I.shape[2]))
+    return img.reshape((img.shape[0] * img.shape[1], img.shape[2]))
 
 
 square = pl.imread('../../data/square.png').astype(np.float64)[:, :, 2]
diff --git a/setup.py b/setup.py
index 91c24d911..9fb1afb7b 100755
--- a/setup.py
+++ b/setup.py
@@ -66,9 +66,8 @@
       license='MIT',
       scripts=[],
       data_files=[],
-      requires=["numpy", "scipy", "cython"],
-      setup_requires=["numpy>=1.16", "scipy>=1.0", "cython>=0.23"],
-      install_requires=["numpy>=1.16", "scipy>=1.0", "cython>=0.23"],
+      setup_requires=["numpy>=1.16", "cython>=0.23"],
+      install_requires=["numpy>=1.16", "scipy>=1.0"],
       classifiers=[
           'Development Status :: 5 - Production/Stable',
           'Intended Audience :: Developers',