diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 550c13b8..3707fd56 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -10,7 +10,7 @@ The Mosquitto project has been created to provide a light weight, open-source
 implementation, of an MQTT broker to allow new, existing, and emerging
 applications for Machine-to-Machine (M2M) and Internet of Things (IoT).
 
-- <http://mosquitto.org/>
+- <https://mosquitto.org/>
 - <https://projects.eclipse.org/projects/technology.mosquitto>
 
 
@@ -19,7 +19,7 @@ Source
 
 The Mosquitto code is stored in a git repository.
 
-- http://github.com/eclipse/mosquitto
+- https://github.com/eclipse/mosquitto
 
 You can contribute bugfixes and new features by sending pull requests through GitHub.
 
diff --git a/client/sub_client.c b/client/sub_client.c
index 8cab3875..28a71b87 100644
--- a/client/sub_client.c
+++ b/client/sub_client.c
@@ -268,7 +268,7 @@ void print_usage(void)
 	printf("           socks5h://[username[:password]@]hostname[:port]\n");
 	printf("           Only \"none\" and \"username\" authentication is supported.\n");
 #endif
-	printf("\nSee http://mosquitto.org/ for more information.\n\n");
+	printf("\nSee https://mosquitto.org/ for more information.\n\n");
 }
 
 int main(int argc, char *argv[])
diff --git a/man/manpage.xsl b/man/manpage.xsl
index ec4e6b70..a5c60503 100644
--- a/man/manpage.xsl
+++ b/man/manpage.xsl
@@ -6,7 +6,7 @@
 	<xsl:param name="man.endnotes.list.enabled">0</xsl:param>
 	<xsl:param name="man.endnotes.are.numbered">0</xsl:param>
 	<!-- But if we do, set a base url for the relative links. -->
-	<xsl:param name="man.base.url.for.relative.links">http://mosquitto.org/man/</xsl:param>
+	<xsl:param name="man.base.url.for.relative.links">https://mosquitto.org/man/</xsl:param>
 	<!-- Don't output filename when generating. -->
 	<xsl:param name="man.output.quietly" select="1"></xsl:param>
 	<!-- Generate ansi style function synopses. -->
diff --git a/readme.md b/readme.md
index ee038fbc..22aeab53 100644
--- a/readme.md
+++ b/readme.md
@@ -11,19 +11,20 @@ subscribing.
 See the following links for more information on MQTT:
 
 - Community page: <http://mqtt.org/>
-- MQTT v3.1.1 standard: <http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/mqtt-v3.1.1.html>
+- MQTT v3.1.1 standard: <https://docs.oasis-open.org/mqtt/mqtt/v3.1.1/mqtt-v3.1.1.html>
+- MQTT v5.0 standard: <https://docs.oasis-open.org/mqtt/mqtt/v5.0/mqtt-v5.0.html>
 
 Mosquitto project information is available at the following locations:
 
-- Main homepage: <http://mosquitto.org/>
+- Main homepage: <https://mosquitto.org/>
 - Find existing bugs or submit a new bug: <https://github.com/eclipse/mosquitto/issues>
 - Source code repository: <https://github.com/eclipse/mosquitto>
 
-There is also a public test server available at <http://test.mosquitto.org/>
+There is also a public test server available at <https://test.mosquitto.org/>
 
 ## Installing
 
-See <http://mosquitto.org/download/> for details on installing binaries for
+See <https://mosquitto.org/download/> for details on installing binaries for
 various platforms.
 
 ## Quick start
@@ -44,17 +45,17 @@ And to publish a message:
 ## Documentation
 
 Documentation for the broker, clients and client library API can be found in
-the man pages, which are available online at <http://mosquitto.org/man/>. There
+the man pages, which are available online at <https://mosquitto.org/man/>. There
 are also pages with an introduction to the features of MQTT, the
 `mosquitto_passwd` utility for dealing with username/passwords, and a
 description of the configuration file options available for the broker.
 
-Detailed client library API documentation can be found at <http://mosquitto.org/api/>
+Detailed client library API documentation can be found at <https://mosquitto.org/api/>
 
 ## Building from source
 
 To build from source the recommended route for end users is to download the
-archive from <http://mosquitto.org/download/>.
+archive from <https://mosquitto.org/download/>.
 
 On Windows and Mac, use `cmake` to build. On other platforms, just run `make`
 to build. For Windows, see also `readme-windows.md`.
diff --git a/src/mosquitto_passwd.c b/src/mosquitto_passwd.c
index f0e5853d..afe3e199 100644
--- a/src/mosquitto_passwd.c
+++ b/src/mosquitto_passwd.c
@@ -130,7 +130,7 @@ void print_usage(void)
 	printf(" -c : create a new password file. This will overwrite existing files.\n");
 	printf(" -D : delete the username rather than adding/updating its password.\n");
 	printf(" -U : update a plain text password file to use hashed passwords.\n");
-	printf("\nSee http://mosquitto.org/ for more information.\n\n");
+	printf("\nSee https://mosquitto.org/ for more information.\n\n");
 }
 
 int output_new_password(FILE *fptr, const char *username, const char *password)