diff --git a/examples/plot_afq_callosal.py b/examples/plot_afq_callosal.py
index 8da462eec..763d6bbcf 100644
--- a/examples/plot_afq_callosal.py
+++ b/examples/plot_afq_callosal.py
@@ -10,6 +10,7 @@
 import plotly
 
 from AFQ import api
+from AFQ.mask import RoiMask
 import AFQ.data as afd
 
 ##########################################################################
@@ -21,6 +22,20 @@
 
 afd.organize_stanford_data()
 
+##########################################################################
+# Set tractography parameters (optional)
+# ---------------------
+# We make this tracking_params which we will pass to the AFQ object
+# which specifies that we want 100,000 seeds randomly distributed
+# in the ROIs of every bundle.
+#
+# We only do this to make this example faster and consume less space.
+
+tracking_params = dict(seed_mask=RoiMask(),
+                       n_seeds=10000,
+                       random_seeds=True,
+                       rng_seed=42)
+
 ##########################################################################
 # Initialize an AFQ object:
 # -------------------------
diff --git a/examples/plot_afq_reco80.py b/examples/plot_afq_reco80.py
index c33341860..6397e9890 100644
--- a/examples/plot_afq_reco80.py
+++ b/examples/plot_afq_reco80.py
@@ -23,6 +23,19 @@
 
 afd.organize_stanford_data()
 
+##########################################################################
+# Set tractography parameters (optional)
+# ---------------------
+# We make this tracking_params which we will pass to the AFQ object
+# which specifies that we want 50,000 seeds randomly distributed
+# in the white matter.
+#
+# We only do this to make this example faster and consume less space.
+
+tracking_params = dict(n_seeds=50000,
+                       random_seeds=True,
+                       rng_seed=42)
+
 ##########################################################################
 # Initialize an AFQ object:
 # -------------------------