diff --git a/src/components/cronet/cronet_context.cc b/src/components/cronet/cronet_context.cc
index da976be8f9..6f25b82636 100644
--- a/src/components/cronet/cronet_context.cc
+++ b/src/components/cronet/cronet_context.cc
@@ -12,6 +12,7 @@
 #include <map>
 #include <memory>
 #include <set>
+#include <string>
 #include <utility>
 
 #include "base/base64.h"
@@ -53,7 +54,10 @@
 #include "net/log/net_log_util.h"
 #include "net/net_buildflags.h"
 #include "net/nqe/network_quality_estimator_params.h"
+#include "net/proxy_resolution/configured_proxy_resolution_service.h"
+#include "net/proxy_resolution/proxy_config.h"
 #include "net/proxy_resolution/proxy_config_service_fixed.h"
+#include "net/proxy_resolution/proxy_config_with_annotation.h"
 #include "net/proxy_resolution/proxy_resolution_service.h"
 #include "net/third_party/quiche/src/quiche/quic/core/quic_versions.h"
 #include "net/url_request/url_request_context.h"
@@ -359,9 +363,21 @@ CronetContext::NetworkTasks::BuildDefaultURLRequestContext(
   context_config_->ConfigureURLRequestContextBuilder(&context_builder);
   SetSharedURLRequestContextBuilderConfig(&context_builder);
 
-  context_builder.set_proxy_resolution_service(
-      cronet::CreateProxyResolutionService(std::move(proxy_config_service),
-                                           g_net_log.Get().net_log()));
+  const base::Value* proxy_server =
+      context_config_->effective_experimental_options.Find("proxy_server");
+  std::string proxy_server_str = "direct://";
+  if (proxy_server != nullptr && proxy_server->is_string()) {
+    proxy_server_str = proxy_server->GetString();
+  }
+  net::ProxyConfig proxy_config;
+  proxy_config.proxy_rules().ParseFromString(proxy_server_str);
+  auto proxy_service =
+      net::ConfiguredProxyResolutionService::CreateWithoutProxyResolver(
+          std::make_unique<net::ProxyConfigServiceFixed>(
+              net::ProxyConfigWithAnnotation(proxy_config,
+                                             MISSING_TRAFFIC_ANNOTATION)),
+          g_net_log.Get().net_log());
+  context_builder.set_proxy_resolution_service(std::move(proxy_service));
 
   if (context_config_->enable_network_quality_estimator) {
     std::unique_ptr<net::NetworkQualityEstimatorParams> nqe_params =
diff --git a/src/components/cronet/cronet_global_state_stubs.cc b/src/components/cronet/cronet_global_state_stubs.cc
index 9afd400bc6..ff55b51348 100644
--- a/src/components/cronet/cronet_global_state_stubs.cc
+++ b/src/components/cronet/cronet_global_state_stubs.cc
@@ -62,15 +62,13 @@ void PostTaskToInitThread(const base::Location& posted_from,
 
 std::unique_ptr<net::ProxyConfigService> CreateProxyConfigService(
     const scoped_refptr<base::SequencedTaskRunner>& io_task_runner) {
-  return net::ProxyConfigService::CreateSystemProxyConfigService(
-      io_task_runner);
+  return nullptr;
 }
 
 std::unique_ptr<net::ProxyResolutionService> CreateProxyResolutionService(
     std::unique_ptr<net::ProxyConfigService> proxy_config_service,
     net::NetLog* net_log) {
-  return net::ConfiguredProxyResolutionService::CreateUsingSystemProxyResolver(
-      std::move(proxy_config_service), net_log, /*quick_check_enabled=*/true);
+  return nullptr;
 }
 
 std::string CreateDefaultUserAgent(const std::string& partial_user_agent) {
diff --git a/src/components/cronet/url_request_context_config.cc b/src/components/cronet/url_request_context_config.cc
index 73daeb933b..8545d95d49 100644
--- a/src/components/cronet/url_request_context_config.cc
+++ b/src/components/cronet/url_request_context_config.cc
@@ -757,6 +757,14 @@ void URLRequestContextConfig::SetContextBuilderExperimentalOptions(
         continue;
       }
       session_params->spdy_go_away_on_ip_change = iter->second.GetBool();
+    } else if (iter->first == "proxy_server") {
+      if (!iter->second.is_string()) {
+        LOG(ERROR) << "\"" << iter->first << "\" config params \""
+                   << iter->second << "\" is not a string";
+        effective_experimental_options.Remove(iter->first);
+        continue;
+      }
+      // Handled in CronetContext::NetworkTasks::BuildDefaultURLRequestContext.
     } else {
       LOG(WARNING) << "Unrecognized Cronet experimental option \""
                    << iter->first << "\" with params \"" << iter->second;