diff --git a/templates/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile.template b/templates/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile.template
index 6232e081eb986f33abe266c3b3f02cee280dab8a..258d29aa970a397c6bc8763ed5451a4b692f73f0 100644
--- a/templates/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile.template
+++ b/templates/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile.template
@@ -46,11 +46,6 @@
   RUN curl -sS https://getcomposer.org/installer | php
   RUN mv composer.phar /usr/local/bin/composer
   
-  # As an attempt to work around #4212, try to prefetch Protobuf-PHP dependency
-  # into composer cache to prevent "composer install" from cloning on each build.
-  RUN git clone --mirror https://github.com/stanley-cheung/Protobuf-PHP.git ${'\\'}
-    /root/.composer/cache/vcs/git-github.com-stanley-cheung-Protobuf-PHP.git/
-  
   # Download the patched PHP protobuf so that PHP gRPC clients can be generated
   # from proto3 schemas.
   RUN git clone https://github.com/stanley-cheung/Protobuf-PHP.git /var/local/git/protobuf-php
diff --git a/templates/tools/dockerfile/stress_test/grpc_interop_stress_php/Dockerfile.template b/templates/tools/dockerfile/stress_test/grpc_interop_stress_php/Dockerfile.template
index f8dc07947420c82f2038128aa9431230e9c1a12e..13a250eb31caf1f16ebab50538313cb34ba66d3d 100644
--- a/templates/tools/dockerfile/stress_test/grpc_interop_stress_php/Dockerfile.template
+++ b/templates/tools/dockerfile/stress_test/grpc_interop_stress_php/Dockerfile.template
@@ -47,11 +47,6 @@
   RUN curl -sS https://getcomposer.org/installer | php
   RUN mv composer.phar /usr/local/bin/composer
   
-  # As an attempt to work around #4212, try to prefetch Protobuf-PHP dependency
-  # into composer cache to prevent "composer install" from cloning on each build.
-  RUN git clone --mirror https://github.com/stanley-cheung/Protobuf-PHP.git ${'\\'}
-    /root/.composer/cache/vcs/git-github.com-stanley-cheung-Protobuf-PHP.git/
-  
   # Download the patched PHP protobuf so that PHP gRPC clients can be generated
   # from proto3 schemas.
   RUN git clone https://github.com/stanley-cheung/Protobuf-PHP.git /var/local/git/protobuf-php
diff --git a/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile b/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile
index ef27af636144c506b70daf5acb08c34130494401..fd13515a06e0abe028a1b113a4f9ed43092a4963 100644
--- a/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile
+++ b/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile
@@ -122,11 +122,6 @@ RUN /bin/bash -l -c "rvm all do gem install ronn rake"
 RUN curl -sS https://getcomposer.org/installer | php
 RUN mv composer.phar /usr/local/bin/composer
 
-# As an attempt to work around #4212, try to prefetch Protobuf-PHP dependency
-# into composer cache to prevent "composer install" from cloning on each build.
-RUN git clone --mirror https://github.com/stanley-cheung/Protobuf-PHP.git \
-  /root/.composer/cache/vcs/git-github.com-stanley-cheung-Protobuf-PHP.git/
-
 # Download the patched PHP protobuf so that PHP gRPC clients can be generated
 # from proto3 schemas.
 RUN git clone https://github.com/stanley-cheung/Protobuf-PHP.git /var/local/git/protobuf-php
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_php/Dockerfile b/tools/dockerfile/stress_test/grpc_interop_stress_php/Dockerfile
index 4adefe5d57b7e787b0ac3d0892ff4460a49a1398..0716be5a9ddb6b0bdcdcaab0b72dcb8f446e6fb7 100644
--- a/tools/dockerfile/stress_test/grpc_interop_stress_php/Dockerfile
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_php/Dockerfile
@@ -127,11 +127,6 @@ RUN /bin/bash -l -c "rvm all do gem install ronn rake"
 RUN curl -sS https://getcomposer.org/installer | php
 RUN mv composer.phar /usr/local/bin/composer
 
-# As an attempt to work around #4212, try to prefetch Protobuf-PHP dependency
-# into composer cache to prevent "composer install" from cloning on each build.
-RUN git clone --mirror https://github.com/stanley-cheung/Protobuf-PHP.git \
-  /root/.composer/cache/vcs/git-github.com-stanley-cheung-Protobuf-PHP.git/
-
 # Download the patched PHP protobuf so that PHP gRPC clients can be generated
 # from proto3 schemas.
 RUN git clone https://github.com/stanley-cheung/Protobuf-PHP.git /var/local/git/protobuf-php