diff --git a/hpb/backend/upb/interop.h b/hpb/backend/upb/interop.h
index c899cb6fef..1c219845ed 100644
--- a/hpb/backend/upb/interop.h
+++ b/hpb/backend/upb/interop.h
@@ -10,6 +10,8 @@
 
 // The sole public header in hpb/backend/upb
 
+#include <cstring>
+
 #include "absl/strings/string_view.h"
 #include "google/protobuf/hpb/internal/internal.h"
 #include "google/protobuf/hpb/ptr.h"
@@ -111,6 +113,14 @@ inline absl::string_view FromUpbStringView(upb_StringView str) {
   return absl::string_view(str.data, str.size);
 }
 
+inline upb_StringView CopyToUpbStringView(absl::string_view str,
+                                          upb_Arena* arena) {
+  const size_t str_size = str.size();
+  char* buffer = static_cast<char*>(upb_Arena_Malloc(arena, str_size));
+  memcpy(buffer, str.data(), str_size);
+  return upb_StringView_FromDataAndSize(buffer, str_size);
+}
+
 }  // namespace hpb::interop::upb
 
 #endif  // GOOGLE_PROTOBUF_HPB_BACKEND_UPB_INTEROP_H__
diff --git a/hpb/hpb.h b/hpb/hpb.h
index da47212483..b84b0534ab 100644
--- a/hpb/hpb.h
+++ b/hpb/hpb.h
@@ -37,15 +37,6 @@
 namespace hpb {
 class ExtensionRegistry;
 
-// TODO: update bzl and move to upb runtime / protos.cc.
-inline upb_StringView UpbStrFromStringView(absl::string_view str,
-                                           upb_Arena* arena) {
-  const size_t str_size = str.size();
-  char* buffer = static_cast<char*>(upb_Arena_Malloc(arena, str_size));
-  memcpy(buffer, str.data(), str_size);
-  return upb_StringView_FromDataAndSize(buffer, str_size);
-}
-
 // This type exists to work around an absl type that has not yet been
 // released.
 struct SourceLocation {
diff --git a/hpb_generator/gen_accessors.cc b/hpb_generator/gen_accessors.cc
index 3d68aa920f..9422df8104 100644
--- a/hpb_generator/gen_accessors.cc
+++ b/hpb_generator/gen_accessors.cc
@@ -234,7 +234,7 @@ void WriteAccessorsInSource(const protobuf::Descriptor* desc, Output& output) {
         output(
             R"cc(
               void $0::set_$2($1 value) {
-                $4_set_$3(msg_, ::hpb::UpbStrFromStringView(value, $5));
+                $4_set_$3(msg_, hpb::interop::upb::CopyToUpbStringView(value, $5));
               }
             )cc",
             class_name, CppConstType(field), resolved_field_name,
@@ -353,7 +353,8 @@ void WriteMapAccessorDefinitions(const protobuf::Descriptor* message,
         R"cc(
           bool $0::set_$1($2 key, $3 value) {
             $5return $4_$7_set(
-                msg_, $6, ::hpb::UpbStrFromStringView(value, arena_), arena_);
+                msg_, $6, hpb::interop::upb::CopyToUpbStringView(value, arena_),
+                arena_);
           }
         )cc",
         class_name, resolved_field_name, CppConstType(key), CppConstType(val),
diff --git a/hpb_generator/gen_repeated_fields.cc b/hpb_generator/gen_repeated_fields.cc
index 0af6b54af6..bf67fe7838 100644
--- a/hpb_generator/gen_repeated_fields.cc
+++ b/hpb_generator/gen_repeated_fields.cc
@@ -219,7 +219,9 @@ void WriteRepeatedStringAccessor(const protobuf::Descriptor* message,
   output(
       R"cc(
         bool $0::add_$2($1 val) {
-          return $3_add_$4(msg_, ::hpb::UpbStrFromStringView(val, arena_), arena_);
+          return $3_add_$4(msg_,
+                           hpb::interop::upb::CopyToUpbStringView(val, arena_),
+                           arena_);
         }
       )cc",
       class_name, CppConstType(field), resolved_field_name,
@@ -230,7 +232,7 @@ void WriteRepeatedStringAccessor(const protobuf::Descriptor* message,
           size_t len;
           auto* ptr = $3_mutable_$4(msg_, &len);
           assert(index < len);
-          *(ptr + index) = ::hpb::UpbStrFromStringView(val, arena_);
+          *(ptr + index) = hpb::interop::upb::CopyToUpbStringView(val, arena_);
         }
       )cc",
       class_name, CppConstType(field), resolved_field_name,