diff --git a/app/src/server.c b/app/src/server.c
index 85b1b6b8..9acaf704 100644
--- a/app/src/server.c
+++ b/app/src/server.c
@@ -261,7 +261,7 @@ server_connect_to(struct server *server) {
 
         server->control_socket = net_accept(server->server_socket);
         if (server->control_socket == INVALID_SOCKET) {
-            // the video_socket will be clean up on destroy
+            // the video_socket will be cleaned up on destroy
             return false;
         }
 
diff --git a/app/src/sys/win/command.c b/app/src/sys/win/command.c
index f23730a0..0e6bc7a9 100644
--- a/app/src/sys/win/command.c
+++ b/app/src/sys/win/command.c
@@ -7,7 +7,7 @@
 static int
 build_cmd(char *cmd, size_t len, const char *const argv[]) {
     // Windows command-line parsing is WTF:
-    // <http://daviddeley.com/autohotkey/parameters/parameters.htm#WINPASS>
+    // <https://daviddeley.com/autohotkey/parameters/parameters.htm#WINPASS>
     // only make it work for this very specific program
     // (don't handle escaping nor quotes)
     size_t ret = xstrjoin(cmd, argv, ' ', len);
diff --git a/config/checkstyle/checkstyle.xml b/config/checkstyle/checkstyle.xml
index 63ee315a..798814d9 100644
--- a/config/checkstyle/checkstyle.xml
+++ b/config/checkstyle/checkstyle.xml
@@ -54,7 +54,7 @@ page at http://checkstyle.sourceforge.net/config.html -->
     <module name="SuppressWarningsHolder"/>
 
     <!-- Checks for imports                              -->
-    <!-- See http://checkstyle.sf.net/config_import.html -->
+    <!-- See http://checkstyle.sf.net/config_imports.html -->
     <module name="AvoidStarImport">
       <property name="allowStaticMemberImports" value="true" />
     </module>
@@ -99,7 +99,7 @@ page at http://checkstyle.sourceforge.net/config.html -->
     <module name="WhitespaceAround" />
 
     <!-- Modifier Checks                                    -->
-    <!-- See http://checkstyle.sf.net/config_modifiers.html -->
+    <!-- See http://checkstyle.sf.net/config_modifier.html -->
     <module name="ModifierOrder" />
     <module name="RedundantModifier" />
 
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 430dfabc..c7d58b1d 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.5.1-all.zip
+distributionUrl=https://services.gradle.org/distributions/gradle-5.5.1-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists