diff --git a/templates/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile.template b/templates/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile.template
index 476f9d3d3eb01ed6c52d1a0eaf6235e91a02d179..a293bae8bc13f1b8eb98acc938a108d138bf73af 100644
--- a/templates/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile.template
+++ b/templates/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile.template
@@ -45,11 +45,6 @@
   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 4cd069da34e6708c44716936833a228ecf0b88c2..df61808937f1582f753272d0cf7ddd5b70c0ae96 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
@@ -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/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile b/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile
index a41153199766ddff611e8a92c98facd71c1cbd39..4e94db247898d7c04f91f071a049cf301fab5730 100644
--- a/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile
+++ b/tools/dockerfile/interoptest/grpc_interop_php/Dockerfile
@@ -107,11 +107,6 @@ 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 bdac01ae8673975b0870cb95f4bdd402ceff919a..13afa1577f9cc0a902f51a4a44d3b6e09622ea66 100644
--- a/tools/dockerfile/stress_test/grpc_interop_stress_php/Dockerfile
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_php/Dockerfile
@@ -112,11 +112,6 @@ 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