diff --git a/INSTALL b/INSTALL
index 4f36c7ff54..63c79198b9 100644
--- a/INSTALL
+++ b/INSTALL
@@ -83,7 +83,7 @@ translations or you change the translation files themselves (po/*.po)
 files, you will need to have the GNU gettext package installed to
 compile LyX with up-to-date translations (at least gettext version
 0.16.1 is needed). You can get the latest version from:
-	ftp://ftp.gnu.org/gnu/gettext/
+	https://ftp.gnu.org/gnu/gettext/
 
 
 Creating the Makefile
diff --git a/INSTALL.MacOSX b/INSTALL.MacOSX
index 3acceb66a0..e8a0d00e6e 100644
--- a/INSTALL.MacOSX
+++ b/INSTALL.MacOSX
@@ -26,8 +26,7 @@ well.
 1. Qt/Mac Opensource Edition, version 4.
 
 This library is GPL-licensed and can be downloaded from
-<http://trolltech.com/developer/downloads/qt/mac/>.
-An alternative location is <ftp://ftp.qt.nokia.com/qt/source>.
+https://www.qt.io.
 To compile it, create a directory where you want to install Qt4.
 In the following, the full path to this directory is called /path/to/Qt4
 Decompress Qt/Mac in a convenient directory, cd to the top of the
@@ -90,7 +89,7 @@ using:
 
 5. To build with included spell checker (ASpell):
 The aspell library is GPL-licensed and can be downloaded from
-ftp://ftp.gnu.org/gnu/aspell or one of the mirrors.
+https://ftp.gnu.org/gnu/aspell or one of the mirrors.
 At the time of writing aspell-0.60.tar.gz is the current version.
 Unpack the tarball in the same directory where you placed the
 git checkout or LyX tarball.
diff --git a/INSTALL.cmake b/INSTALL.cmake
index 83f892c470..316579e834 100644
--- a/INSTALL.cmake
+++ b/INSTALL.cmake
@@ -28,7 +28,7 @@ Building LyX with CMake
     Windows specific
 
         On Windows install the supplementary modules:
-        * Visual Studio 2015: ftp://ftp.lyx.org/pub/lyx/devel/win_deps/lyx-windows-deps-msvc2015.zip
+        * Visual Studio 2015: http://ftp.lyx.org/pub/lyx/devel/win_deps/lyx-windows-deps-msvc2015.zip
                 or use the option LYX_DEPENDENCIES_DOWNLOAD, then you have to add
                 these paths to your PATH variable:
                   <build-dir>\lyx-windows-deps-msvc2015\bin
diff --git a/README b/README
index 9fe45fb4d7..2bb7e6295d 100644
--- a/README
+++ b/README
@@ -130,7 +130,7 @@ Internet resources of relevance to LyX
 	http://wiki.lyx.org/
 
     The main LyX archive site:
-	ftp://ftp.lyx.org/pub/lyx/
+	http://ftp.lyx.org/pub/lyx/
 
     The LyX Development page has information about the development
     effort. LyX is under Git version control, so you can get the very