diff --git a/bazel/external/quiche.BUILD b/bazel/external/quiche.BUILD
index 0563a6edfea37..b287afa1dc695 100644
--- a/bazel/external/quiche.BUILD
+++ b/bazel/external/quiche.BUILD
@@ -26,6 +26,10 @@ licenses(["notice"])  # Apache 2
 # should remain largely the same.
 
 load(":genrule_cmd.bzl", "genrule_cmd")
+load(
+    "@envoy//bazel:envoy_build_system.bzl",
+    "envoy_cc_test",
+)
 
 src_files = glob([
     "**/*.h",
@@ -118,9 +122,11 @@ cc_library(
         "quiche/quic/platform/api/quic_flag_utils.h",
         "quiche/quic/platform/api/quic_iovec.h",
         "quiche/quic/platform/api/quic_prefetch.h",
+        "quiche/quic/platform/api/quic_ptr_util.h",
+        "quiche/quic/platform/api/quic_str_cat.h",
         "quiche/quic/platform/api/quic_string.h",
         "quiche/quic/platform/api/quic_string_piece.h",
-        "quiche/quic/platform/api/quic_ptr_util.h",
+        "quiche/quic/platform/api/quic_string_utils.h",
         "quiche/quic/platform/api/quic_uint128.h",
         # TODO: uncomment the following files as implementations are added.
         # "quiche/quic/platform/api/quic_bug_tracker.h",
@@ -150,8 +156,6 @@ cc_library(
         # "quiche/quic/platform/api/quic_sleep.h",
         # "quiche/quic/platform/api/quic_socket_address.h",
         # "quiche/quic/platform/api/quic_stack_trace.h",
-        # "quiche/quic/platform/api/quic_str_cat.h",
-        # "quiche/quic/platform/api/quic_string_utils.h",
         # "quiche/quic/platform/api/quic_test.h",
         # "quiche/quic/platform/api/quic_test_loopback.h",
         # "quiche/quic/platform/api/quic_test_mem_slice_vector.h",
@@ -164,3 +168,12 @@ cc_library(
         "@envoy//source/extensions/quic_listeners/quiche/platform:quic_platform_base_impl_lib",
     ],
 )
+
+envoy_cc_test(
+    name = "quic_platform_test",
+    srcs = ["quiche/quic/platform/api/quic_string_utils_test.cc"],
+    repository = "@envoy",
+    deps = [
+        ":quic_platform",
+    ],
+)
diff --git a/source/extensions/quic_listeners/quiche/platform/BUILD b/source/extensions/quic_listeners/quiche/platform/BUILD
index 12d7fd4fb1e3a..8687dd1cb0b6f 100644
--- a/source/extensions/quic_listeners/quiche/platform/BUILD
+++ b/source/extensions/quic_listeners/quiche/platform/BUILD
@@ -70,6 +70,8 @@ envoy_cc_library(
     name = "quic_platform_impl_lib",
     hdrs = [
         "quic_mutex_impl.h",
+        "quic_str_cat_impl.h",
+        "quic_string_utils_impl.h",
     ],
     external_deps = [
         "quiche_quic_platform_base",
diff --git a/source/extensions/quic_listeners/quiche/platform/quic_str_cat_impl.h b/source/extensions/quic_listeners/quiche/platform/quic_str_cat_impl.h
new file mode 100644
index 0000000000000..f689f40a6204a
--- /dev/null
+++ b/source/extensions/quic_listeners/quiche/platform/quic_str_cat_impl.h
@@ -0,0 +1,23 @@
+#pragma once
+
+#include "absl/strings/str_cat.h"
+#include "fmt/printf.h"
+#include "quiche/quic/platform/api/quic_string.h"
+
+// NOLINT(namespace-envoy)
+
+// This file is part of the QUICHE platform implementation, and is not to be
+// consumed or referenced directly by other Envoy code. It serves purely as a
+// porting layer for QUICHE.
+
+namespace quic {
+
+template <typename... Args> inline QuicString QuicStrCatImpl(const Args&... args) {
+  return absl::StrCat(args...);
+}
+
+template <typename... Args> inline QuicString QuicStringPrintfImpl(const Args&... args) {
+  return fmt::sprintf(std::forward<const Args&>(args)...);
+}
+
+} // namespace quic
diff --git a/source/extensions/quic_listeners/quiche/platform/quic_string_utils_impl.h b/source/extensions/quic_listeners/quiche/platform/quic_string_utils_impl.h
new file mode 100644
index 0000000000000..b3ab8277df196
--- /dev/null
+++ b/source/extensions/quic_listeners/quiche/platform/quic_string_utils_impl.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include "absl/strings/str_cat.h"
+#include "quiche/quic/platform/api/quic_string.h"
+
+// NOLINT(namespace-envoy)
+
+// This file is part of the QUICHE platform implementation, and is not to be
+// consumed or referenced directly by other Envoy code. It serves purely as a
+// porting layer for QUICHE.
+
+namespace quic {
+
+template <typename... Args> inline void QuicStrAppendImpl(QuicString* output, const Args&... args) {
+  absl::StrAppend(output, args...);
+}
+
+} // namespace quic