diff --git a/setup.py b/setup.py
index 08a0925..465dc13 100644
--- a/setup.py
+++ b/setup.py
@@ -49,7 +49,6 @@
         # Until this issue is closed
         # https://github.com/googleapis/google-cloud-python/issues/10566
         "google-api-core[grpc] >= 1.28.0, <3.0.0dev",
-        "libcst >= 0.2.5",
         "proto-plus >= 1.4.0",
         "packaging >= 14.3",
     ),
diff --git a/testing/constraints-3.6.txt b/testing/constraints-3.6.txt
index 61f0ec4..5c1659b 100644
--- a/testing/constraints-3.6.txt
+++ b/testing/constraints-3.6.txt
@@ -6,6 +6,5 @@
 # e.g., if setup.py has "foo >= 1.14.0, < 2.0.0dev",
 # Then this file should have foo==1.14.0
 google-api-core==1.28.0
-libcst==0.2.5
 proto-plus==1.4.0
 packaging==14.3