diff --git a/src/pip/_internal/req/req_install.py b/src/pip/_internal/req/req_install.py
index 77526283d..450d05090 100644
--- a/src/pip/_internal/req/req_install.py
+++ b/src/pip/_internal/req/req_install.py
@@ -585,7 +585,7 @@ class InstallRequirement(object):
         if "requires" not in build_system:
             raise InstallationError(
                 error_template.format(package=self, reason=(
-                    "it has a 'build-system' table but not the "
+                    "it has a 'build-system' table but not "
                     "'build-system.requires' which is mandatory in the table"
                 ))
             )