diff --git a/README.md b/README.md
index 27e6d526..1c058bc9 100644
--- a/README.md
+++ b/README.md
@@ -25,6 +25,11 @@ Fedora/Ubuntu name
         * Built with Sequoia
         * Built with an internal OpenPGP parser - buggy
           (https://github.com/rpm-software-management/rpm/issues/2512)
+* Optional dependencies:
+    * zchunk (https://github.com/zchunk/zchunk) - zchunk-devel/libzck-dev - disable
+      with -DWITH\_ZCHUNK=OFF
+        * If you build librepo with zchunk support, your application might
+          transitively include zchunk headers.
 * **Test requires:** pygpgme (https://pypi.python.org/pypi/pygpgme/0.1) - python3-pygpgme/python3-gpgme
 * **Test requires:** python3-pyxattr (https://github.com/xattr/xattr) - python3-pyxattr/python3-pyxattr
 
diff --git a/librepo/CMakeLists.txt b/librepo/CMakeLists.txt
index 7615d688..68d78677 100644
--- a/librepo/CMakeLists.txt
+++ b/librepo/CMakeLists.txt
@@ -80,6 +80,7 @@ ENDIF (USE_GPGME)
 
 IF (WITH_ZCHUNK)
     TARGET_LINK_LIBRARIES(librepo ${ZCHUNKLIB_LIBRARIES})
+    SET(PKGCONF_DEPENDENCY_ZCK "zck")
 ENDIF (WITH_ZCHUNK)
 
 SET_TARGET_PROPERTIES(librepo PROPERTIES OUTPUT_NAME "repo")
diff --git a/librepo/librepo.pc.cmake b/librepo/librepo.pc.cmake
index 6ac4e325..f486ed9f 100644
--- a/librepo/librepo.pc.cmake
+++ b/librepo/librepo.pc.cmake
@@ -6,7 +6,7 @@ Name: librepo
 Description: Repodata downloading library.
 Version: @VERSION@
 Requires: glib-2.0
-Requires.private: libcurl openssl libxml-2.0
+Requires.private: libcurl openssl libxml-2.0 @PKGCONF_DEPENDENCY_ZCK@
 Libs: -L${libdir} -lrepo
 Libs.private: -lgpgme -lgpg-error
 Cflags: -I${includedir} -D_FILE_OFFSET_BITS=64