diff --git a/skimage/filter/tests/test_denoise.py b/skimage/filter/tests/test_denoise.py
index cb3b5da3..f81ba07b 100644
--- a/skimage/filter/tests/test_denoise.py
+++ b/skimage/filter/tests/test_denoise.py
@@ -4,6 +4,9 @@ from numpy.testing import run_module_suite, assert_raises, assert_equal
 from skimage import filter, data, color, img_as_float
 
 
+np.random.seed(1234)
+
+
 lena = img_as_float(data.lena()[:256, :256])
 lena_gray = color.rgb2gray(lena)
 
diff --git a/skimage/measure/tests/test_structural_similarity.py b/skimage/measure/tests/test_structural_similarity.py
index ac45072a..ec5ce7ef 100644
--- a/skimage/measure/tests/test_structural_similarity.py
+++ b/skimage/measure/tests/test_structural_similarity.py
@@ -4,6 +4,9 @@ from numpy.testing import assert_equal, assert_raises
 from skimage.measure import structural_similarity as ssim
 
 
+np.random.seed(1234)
+
+
 def test_ssim_patch_range():
     N = 51
     X = (np.random.random((N, N)) * 255).astype(np.uint8)