diff --git a/CMakeLists.txt b/CMakeLists.txt
index e1b66ba13..62646f31f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -39,6 +39,9 @@ OPTION (ENABLE_COVERAGE "Enable support for coverage analysis" OFF)
 OPTION (DEBUG_FUNCTION_NAMES "Print function names on entry and exit" OFF)
 # the shell based scripts got replaced by https://github.com/greenbone/greenbone-feed-sync/
 OPTION (INSTALL_OLD_SYNC_SCRIPTS "Install shell based feed sync scripts" OFF)
+if (INSTALL_OLD_SYNC_SCRIPTS)
+  message (DEPRECATION "The version of greenbone-feed-sync included in gvmd is deprecated in favor of the newer Python version (https://github.com/greenbone/greenbone-feed-sync/) and will be removed in the next major version.")
+endif (INSTALL_OLD_SYNC_SCRIPTS)
 
 ## Retrieve git revision (at configure time)
 include (GetGit)
diff --git a/INSTALL.md b/INSTALL.md
index 5832a4fb9..393491040 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -265,7 +265,31 @@ The UUIDs of all created users can be found using
 ## Keeping the feeds up-to-date
 
 The `gvmd Data`, `SCAP` and `CERT` Feeds should be kept up-to-date by calling the
-`greenbone-feed-sync` script regularely (e.g. via a cron entry):
+`greenbone-feed-sync` script regularly (e.g. via a cron entry).
+
+There are currently two synchronization methods available: The older
+shell-based one included in the gvmd repository and a newer Python-based one
+that also handles the VT synchronization.
+
+### Python-based sync tool
+
+The currently recommended way of synchronizing the gvmd data feeds is the
+Python tool "greenbone-feed-sync", which can be found at
+https://github.com/greenbone/greenbone-feed-sync together with instruction
+for its installation and usage.
+
+When upgrading to the new synchronization tool, the old script should be
+removed to avoid conflicts as both are named "greenbone-feed-sync".
+
+### Legacy shell script
+
+The legacy feed sync script is deprecated and will be removed in the next major
+release of gvmd.
+
+Therefore, installation of it is now disabled by default but can be enabled for
+backward compatibility with the CMake option `-DINSTALL_OLD_SYNC_SCRIPTS=ON`.
+
+The legacy script has to be run for each type of data:
 
     greenbone-feed-sync --type GVMD_DATA
     greenbone-feed-sync --type SCAP
@@ -275,7 +299,6 @@ Please note: The `CERT` feed sync depends on data provided by the `SCAP` feed
 and should be called after syncing the latter.
 You will need the `rsync` tool for a successful synchronization.
 
-
 ## Configure the default OSPD scanner socket path
 
 By default, Manager tries to connect to the default OSPD scanner via the following path: