diff --git a/cmake/SelectZlib.cmake b/cmake/SelectZlib.cmake
index fb4361abc..25c7b2f94 100644
--- a/cmake/SelectZlib.cmake
+++ b/cmake/SelectZlib.cmake
@@ -4,6 +4,7 @@ include(SanitizeBool)
 SanitizeBool(USE_BUNDLED_ZLIB)
 if(USE_BUNDLED_ZLIB STREQUAL ON)
 	set(USE_BUNDLED_ZLIB "Bundled")
+	set(GIT_COMPRESSION_BUILTIN)
 endif()
 
 if(USE_BUNDLED_ZLIB STREQUAL "OFF")
@@ -17,6 +18,7 @@ if(USE_BUNDLED_ZLIB STREQUAL "OFF")
 			list(APPEND LIBGIT2_PC_REQUIRES "zlib")
 		endif()
 		add_feature_info(zlib ON "using system zlib")
+		set(GIT_COMPRESSION_ZLIB 1)
 	else()
 		message(STATUS "zlib was not found; using bundled 3rd-party sources." )
 	endif()
@@ -26,9 +28,11 @@ if(USE_BUNDLED_ZLIB STREQUAL "Chromium")
 	list(APPEND LIBGIT2_DEPENDENCY_INCLUDES "${PROJECT_SOURCE_DIR}/deps/chromium-zlib")
 	list(APPEND LIBGIT2_DEPENDENCY_OBJECTS $<TARGET_OBJECTS:chromium_zlib>)
 	add_feature_info(zlib ON "using (Chromium) bundled zlib")
+	set(GIT_COMPRESSION_BUILTIN 1)
 elseif(USE_BUNDLED_ZLIB OR NOT ZLIB_FOUND)
 	add_subdirectory("${PROJECT_SOURCE_DIR}/deps/zlib" "${PROJECT_BINARY_DIR}/deps/zlib")
 	list(APPEND LIBGIT2_DEPENDENCY_INCLUDES "${PROJECT_SOURCE_DIR}/deps/zlib")
 	list(APPEND LIBGIT2_DEPENDENCY_OBJECTS $<TARGET_OBJECTS:zlib>)
 	add_feature_info(zlib ON "using bundled zlib")
+	set(GIT_COMPRESSION_BUILTIN 1)
 endif()
diff --git a/src/util/git2_features.h.in b/src/util/git2_features.h.in
index 9408f9b00..cd14cc234 100644
--- a/src/util/git2_features.h.in
+++ b/src/util/git2_features.h.in
@@ -66,6 +66,9 @@
 #cmakedefine GIT_SHA256_OPENSSL_DYNAMIC 1
 #cmakedefine GIT_SHA256_MBEDTLS 1
 
+#cmakedefine GIT_COMPRESSION_BUILTIN 1
+#cmakedefine GIT_COMPRESSION_ZLIB 1
+
 #cmakedefine GIT_RAND_GETENTROPY 1
 #cmakedefine GIT_RAND_GETLOADAVG 1