diff --git a/tools/aconfig/src/codegen_cpp.rs b/tools/aconfig/src/codegen_cpp.rs
index 33e54a1..4ad3f4e 100644
--- a/tools/aconfig/src/codegen_cpp.rs
+++ b/tools/aconfig/src/codegen_cpp.rs
@@ -151,12 +151,9 @@
 #ifdef __cplusplus
 
 #include <memory>
-#include <vector>
 
 namespace com::android::aconfig::test {
 
-extern std::vector<int8_t> cache_;
-
 class flag_provider_interface {
 public:
     virtual ~flag_provider_interface() = default;
@@ -359,6 +356,7 @@
     const PROD_SOURCE_FILE_EXPECTED: &str = r#"
 #include "com_android_aconfig_test.h"
 #include <server_configurable_flags/get_flags.h>
+#include <vector>
 
 namespace com::android::aconfig::test {
 
@@ -407,10 +405,10 @@
                 return cache_[2];
             }
 
+    private:
+        std::vector<int8_t> cache_ = std::vector<int8_t>(3, -1);
     };
 
-    std::vector<int8_t> cache_ = std::vector<int8_t>(3, -1);
-
     std::unique_ptr<flag_provider_interface> provider_ =
         std::make_unique<flag_provider>();
 }
diff --git a/tools/aconfig/templates/cpp_exported_header.template b/tools/aconfig/templates/cpp_exported_header.template
index d19c0fa..cc1b18d 100644
--- a/tools/aconfig/templates/cpp_exported_header.template
+++ b/tools/aconfig/templates/cpp_exported_header.template
@@ -18,16 +18,9 @@
 #ifdef __cplusplus
 
 #include <memory>
-{{ if not for_test- }}
-#include <vector>
-{{ -endif }}
 
 namespace {cpp_namespace} \{
 
-{{ if not for_test- }}
-extern std::vector<int8_t> cache_;
-{{ -endif }}
-
 class flag_provider_interface \{
 public:
     virtual ~flag_provider_interface() = default;
diff --git a/tools/aconfig/templates/cpp_source_file.template b/tools/aconfig/templates/cpp_source_file.template
index 91e828a..1bfa4b6 100644
--- a/tools/aconfig/templates/cpp_source_file.template
+++ b/tools/aconfig/templates/cpp_source_file.template
@@ -5,6 +5,8 @@
 {{ if for_test }}
 #include <unordered_map>
 #include <string>
+{{ -else- }}
+#include <vector>
 {{ endif }}
 
 namespace {cpp_namespace} \{
@@ -69,16 +71,15 @@
             {{ -endif }}
         }
         {{ endfor }}
+    private:
+        std::vector<int8_t> cache_ = std::vector<int8_t>({readwrite_count}, -1);
     };
 
-    std::vector<int8_t> cache_ = std::vector<int8_t>({readwrite_count}, -1);
 
 {{ -endif }}
 
 std::unique_ptr<flag_provider_interface> provider_ =
     std::make_unique<flag_provider>();
-
-
 }