diff --git a/proxygen/httpserver/filters/tests/CompressionFilterTest.cpp b/proxygen/httpserver/filters/tests/CompressionFilterTest.cpp
index 96d19be8c..545577139 100644
--- a/proxygen/httpserver/filters/tests/CompressionFilterTest.cpp
+++ b/proxygen/httpserver/filters/tests/CompressionFilterTest.cpp
@@ -36,7 +36,8 @@ MATCHER_P(IOBufEquals,
 
 struct ZlibTest {
   static std::unique_ptr<StreamDecompressor> makeDecompressor() {
-    return std::make_unique<ZlibStreamDecompressor>(CompressionType::GZIP);
+    return std::make_unique<proxygen::decompression::ZlibStreamDecompressor>(
+        CompressionType::GZIP);
   }
   static std::string getExpectedEncoding() {
     return "gzip";
diff --git a/proxygen/lib/http/coro/filters/DecompressionFilter.cpp b/proxygen/lib/http/coro/filters/DecompressionFilter.cpp
index 13257695a..4091c339c 100644
--- a/proxygen/lib/http/coro/filters/DecompressionFilter.cpp
+++ b/proxygen/lib/http/coro/filters/DecompressionFilter.cpp
@@ -105,7 +105,9 @@ void DecompressionIngressFilter::initializeWithHTTPMessage(HTTPMessage& msg) {
     if (it->type == CompressionType::ZSTD) {
       decompressor_ = std::make_unique<ZstdStreamDecompressor>();
     } else {
-      decompressor_ = std::make_unique<ZlibStreamDecompressor>(it->type);
+      decompressor_ =
+          std::make_unique<proxygen::decompression::ZlibStreamDecompressor>(
+              it->type);
     }
   } else if (statsCallback_) {
     statsCallback_->onDecompressionAlgo("");
diff --git a/proxygen/lib/http/coro/filters/test/CompressionFilterTests.cpp b/proxygen/lib/http/coro/filters/test/CompressionFilterTests.cpp
index 2e259b5ed..9565cac58 100644
--- a/proxygen/lib/http/coro/filters/test/CompressionFilterTests.cpp
+++ b/proxygen/lib/http/coro/filters/test/CompressionFilterTests.cpp
@@ -27,7 +27,8 @@ MATCHER_P(IOBufEquals, expected, "") {
 
 struct ZlibTest {
   static std::unique_ptr<StreamDecompressor> makeDecompressor() {
-    return std::make_unique<ZlibStreamDecompressor>(CompressionType::GZIP);
+    return std::make_unique<proxygen::decompression::ZlibStreamDecompressor>(
+        CompressionType::GZIP);
   }
   static std::string getExpectedEncoding() {
     return "gzip";
diff --git a/proxygen/lib/utils/ZlibStreamCompressor.cpp b/proxygen/lib/utils/ZlibStreamCompressor.cpp
index fbe0e6a00..37bef0b93 100644
--- a/proxygen/lib/utils/ZlibStreamCompressor.cpp
+++ b/proxygen/lib/utils/ZlibStreamCompressor.cpp
@@ -68,8 +68,9 @@ void ZlibStreamCompressor::init() {
 
   switch (type_) {
     case CompressionType::GZIP: {
-      auto windowBits = type_ == CompressionType::GZIP ? GZIP_WINDOW_BITS
-                                                       : DEFLATE_WINDOW_BITS;
+      auto windowBits = type_ == CompressionType::GZIP
+                            ? proxygen::decompression::GZIP_WINDOW_BITS
+                            : proxygen::decompression::DEFLATE_WINDOW_BITS;
       status_ = deflateInit2(&zlibStream_,
                              level_,
                              Z_DEFLATED,
diff --git a/proxygen/lib/utils/ZlibStreamDecompressor.cpp b/proxygen/lib/utils/ZlibStreamDecompressor.cpp
index f251b7a17..3f046db43 100644
--- a/proxygen/lib/utils/ZlibStreamDecompressor.cpp
+++ b/proxygen/lib/utils/ZlibStreamDecompressor.cpp
@@ -13,7 +13,7 @@
 
 using folly::IOBuf;
 
-namespace proxygen {
+namespace proxygen::decompression {
 
 void ZlibStreamDecompressor::init(CompressionType type) {
   DCHECK(type_ == CompressionType::NONE) << "Must be uninitialized";
@@ -120,4 +120,4 @@ std::unique_ptr<IOBuf> ZlibStreamDecompressor::decompress(const IOBuf* in) {
   return out;
 }
 
-} // namespace proxygen
+} // namespace proxygen::decompression
diff --git a/proxygen/lib/utils/ZlibStreamDecompressor.h b/proxygen/lib/utils/ZlibStreamDecompressor.h
index 1fb1aaa3d..79e9c444f 100644
--- a/proxygen/lib/utils/ZlibStreamDecompressor.h
+++ b/proxygen/lib/utils/ZlibStreamDecompressor.h
@@ -18,7 +18,7 @@ namespace folly {
 class IOBuf;
 }
 
-namespace proxygen {
+namespace proxygen::decompression {
 
 namespace {
 constexpr uint64_t kZlibDecompressorBufferGrowthDefault = 480;
@@ -74,4 +74,4 @@ class ZlibStreamDecompressor : public StreamDecompressor {
   uint64_t totalInputBytes_{0};
   uint64_t totalOutputBytes_{0};
 };
-} // namespace proxygen
+} // namespace proxygen::decompression
diff --git a/proxygen/lib/utils/test/ZlibTests.cpp b/proxygen/lib/utils/test/ZlibTests.cpp
index 3b164cb30..2cca474f5 100644
--- a/proxygen/lib/utils/test/ZlibTests.cpp
+++ b/proxygen/lib/utils/test/ZlibTests.cpp
@@ -42,7 +42,8 @@ std::unique_ptr<folly::IOBuf> makeBuf(uint32_t size) {
 void verify(CompressionType type,
             std::unique_ptr<IOBuf> original,
             std::unique_ptr<IOBuf> compressed) {
-  auto zd = std::make_unique<ZlibStreamDecompressor>(type);
+  auto zd =
+      std::make_unique<proxygen::decompression::ZlibStreamDecompressor>(type);
 
   auto decompressed = zd->decompress(compressed.get());
   ASSERT_FALSE(zd->hasError()) << "Decompression error. r=" << zd->getStatus();
@@ -177,10 +178,10 @@ TEST_F(ZlibTests, MaxDecompressionRatio_FailsWhenRatioTooSmall) {
   auto compressed = compressBuf(CompressionType::GZIP, original);
   ASSERT_NE(compressed, nullptr);
 
-  auto zd = std::make_unique<ZlibStreamDecompressor>(
+  auto zd = std::make_unique<proxygen::decompression::ZlibStreamDecompressor>(
       CompressionType::GZIP,
-      kZlibDecompressorBufferGrowthDefault,
-      kZlibDecompressorBufferMinsizeDefault,
+      proxygen::decompression::kZlibDecompressorBufferGrowthDefault,
+      proxygen::decompression::kZlibDecompressorBufferMinsizeDefault,
       /*maxDecompressionRatio=*/10);
 
   auto decompressed = zd->decompress(compressed.get());
@@ -196,10 +197,10 @@ TEST_F(ZlibTests, MaxDecompressionRatio_PassesWhenRatioLargeEnough) {
   ASSERT_NE(compressed, nullptr);
 
   // Use a very large ratio so decompression succeeds.
-  auto zd = std::make_unique<ZlibStreamDecompressor>(
+  auto zd = std::make_unique<proxygen::decompression::ZlibStreamDecompressor>(
       CompressionType::GZIP,
-      kZlibDecompressorBufferGrowthDefault,
-      kZlibDecompressorBufferMinsizeDefault,
+      proxygen::decompression::kZlibDecompressorBufferGrowthDefault,
+      proxygen::decompression::kZlibDecompressorBufferMinsizeDefault,
       /*maxDecompressionRatio=*/1000000);
 
   auto decompressed = zd->decompress(compressed.get());
@@ -216,7 +217,8 @@ TEST_F(ZlibTests, MaxDecompressionRatio_PassesWhenUnspecified) {
   ASSERT_NE(compressed, nullptr);
 
   // Default: no ratio limit.
-  auto zd = std::make_unique<ZlibStreamDecompressor>(CompressionType::GZIP);
+  auto zd = std::make_unique<proxygen::decompression::ZlibStreamDecompressor>(
+      CompressionType::GZIP);
 
   auto decompressed = zd->decompress(compressed.get());
   EXPECT_FALSE(zd->hasError());
@@ -233,10 +235,10 @@ TEST_F(ZlibTests, MaxDecompressionRatio_StreamingChunksFailure) {
   auto compressed = compressBuf(CompressionType::GZIP, original);
   ASSERT_NE(compressed, nullptr);
 
-  auto zd = std::make_unique<ZlibStreamDecompressor>(
+  auto zd = std::make_unique<proxygen::decompression::ZlibStreamDecompressor>(
       CompressionType::GZIP,
-      kZlibDecompressorBufferGrowthDefault,
-      kZlibDecompressorBufferMinsizeDefault,
+      proxygen::decompression::kZlibDecompressorBufferGrowthDefault,
+      proxygen::decompression::kZlibDecompressorBufferMinsizeDefault,
       /*maxDecompressionRatio=*/10);
 
   // Split compressed data into small chunks.