diff --git a/templates/tools/dockerfile/test/ruby_debian11_x64/Dockerfile.template b/templates/tools/dockerfile/test/ruby_debian11_x64/Dockerfile.template
index a3fe030644a..69d48822d48 100644
--- a/templates/tools/dockerfile/test/ruby_debian11_x64/Dockerfile.template
+++ b/templates/tools/dockerfile/test/ruby_debian11_x64/Dockerfile.template
@@ -23,5 +23,8 @@
   <%include file="../../ccache.include"/>
   <%include file="../../run_tests_addons.include"/>
 
+  # Seems required by XDS interop tests.
+  RUN python3 -m pip install virtualenv==16.7.9
+
   # Define the default command.
   CMD ["bash"]
diff --git a/tools/dockerfile/test/ruby_debian11_x64/Dockerfile b/tools/dockerfile/test/ruby_debian11_x64/Dockerfile
index d05ee85bf14..7658168e702 100644
--- a/tools/dockerfile/test/ruby_debian11_x64/Dockerfile
+++ b/tools/dockerfile/test/ruby_debian11_x64/Dockerfile
@@ -121,5 +121,8 @@ RUN curl -sSL -o ccache.tar.gz https://github.com/ccache/ccache/releases/downloa
 RUN mkdir /var/local/jenkins
 
 
+# Seems required by XDS interop tests.
+RUN python3 -m pip install virtualenv==16.7.9
+
 # Define the default command.
 CMD ["bash"]