diff --git a/basics.html b/basics.html
index 311c42a6b3065d174593022a83331db3af33b6c0..578f09a3ead4fe75633fe8b4e3df10b0d62a3224 100644
--- a/basics.html
+++ b/basics.html
@@ -820,7 +820,7 @@
             notes:
             - this is a demo chapter, you will all do this in collaboration
               chapter (next one)
-            - what was this **master** again? we have not explained yet
+            - what was this **main** again? we have not explained yet
           </section>
 
           <section id="branch-visual" data-markdown>
@@ -833,7 +833,7 @@
               - create a branch to have a separate history
               - branch is a name attached to a commit
               - the name advances when a new commit is made
-            - **master** is a naming convention for the default branch
+            - **main** is a naming convention for the default branch
             - switch back and forth
             - always imagine git history as a directed graph
               - graph is drawn with new top and old bottom
@@ -844,7 +844,7 @@
           <section id="branch-when-to-use" data-markdown>
             ## when to use branches
 
-            - breaking **master**
+            - breaking **main**
             - something takes longer
             - frequent interruptions
             - (instead of) comment out code
@@ -908,7 +908,7 @@
 
             ```bash
             # resolve branch by merging
-            git switch master
+            git switch main
             git merge branch-name
 
             # delete branch
@@ -917,7 +917,7 @@
 
             notes:
             ```
-            # switch master, lol
+            # switch main, lol
             # merge wip/feature, lol
             # branch -d wip/feature, lol
             ```
@@ -946,7 +946,7 @@
 
             notes:
             - we: new commit
-            - group: fetch, lol, pull upstream master, lol
+            - group: fetch, lol, pull upstream main, lol
             - group: push origin, lol
             - group: branch, switch, commit, push, MR
             - collaboration happens in issues and MR discussion!
@@ -979,7 +979,7 @@
             ```bash
             git fetch upstream
             git switch topic/feature
-            git merge origin/master
+            git merge origin/main
             # fix conflicts
             git push
             ```
@@ -1086,7 +1086,7 @@
             ```bash
             git remote add alice https://...
             git fetch alice
-            git rebase [--interactive] master alice/topic/feature
+            git rebase [--interactive] main alice/topic/feature
             # fix conflicts
             git push
             # manually close merge request
@@ -1102,7 +1102,7 @@
 
             ```bash
             git fetch upstream
-            git rebase origin/master topic/feature
+            git rebase origin/main topic/feature
             # fix conflicts
             # force push because branch history changed
             git push --force
@@ -1136,7 +1136,7 @@
             ```bash
             git remote add alice https://...
             git fetch alice
-            git switch master
+            git switch main
             git merge alice/topic/feature
             # fix conflicts
             git push
diff --git a/img/git-remote-contributor.dot b/img/git-remote-contributor.dot
index e4fa7557dfcceb70dc24d51d9ad94bd16e8e2fb2..ad79f6df5f9dcf94b4db5be9f5fe8484e50f239a 100644
--- a/img/git-remote-contributor.dot
+++ b/img/git-remote-contributor.dot
@@ -6,7 +6,7 @@ digraph {
 
         node [color = orchid]
 
-        omaster[label = "master"]
+        omain[label = "main"]
     }
 
     subgraph clusterlocal {
@@ -14,7 +14,7 @@ digraph {
 
         node [color = orchid]
 
-        master[label = "master"]
+        main[label = "main"]
     }
 
     subgraph clusterupstream {
@@ -22,11 +22,11 @@ digraph {
 
         node [color = limegreen]
 
-        umaster[label = "master"]
+        umain[label = "main"]
     }
 
-    omaster -> master [label = "git pull"]
-    master -> omaster [label = "git push", constraint = false]
-    umaster -> master [label = "git pull upstream master", constraint = false]
-    omaster -> umaster [label = "pull request (GitHub)\nmerge request (GitLab)", constraint = false]
+    omain -> main [label = "git pull"]
+    main -> omain [label = "git push", constraint = false]
+    umain -> main [label = "git pull upstream main", constraint = false]
+    omain -> umain [label = "pull request (GitHub)\nmerge request (GitLab)", constraint = false]
 }
diff --git a/img/git-remote-maintainer.dot b/img/git-remote-maintainer.dot
index acd181de432afa3d5886ea7a2baecd0878043b0e..3c5cc38d71962bc7bccc1d91aa78bbb702064757 100644
--- a/img/git-remote-maintainer.dot
+++ b/img/git-remote-maintainer.dot
@@ -6,7 +6,7 @@ digraph {
 
         node [color = orchid]
 
-        omaster[label = "master"]
+        omain[label = "main"]
     }
 
     subgraph clusterlocal {
@@ -14,7 +14,7 @@ digraph {
 
         node [color = orchid]
 
-        master[label = "master"]
+        main[label = "main"]
     }
 
     subgraph clusteralice {
@@ -22,7 +22,7 @@ digraph {
 
         node [color = limegreen]
 
-        amaster[label = "master"]
+        amain[label = "main"]
     }
 
     subgraph clusterbob {
@@ -30,11 +30,11 @@ digraph {
 
         node [color = lightskyblue]
 
-        bmaster[label = "master"]
+        bmain[label = "main"]
     }
 
-    omaster -> master [label = "git pull"]
-    master -> omaster [label = "git push", constraint = false]
-    amaster -> master [label = "git pull alice", constraint = false]
-    bmaster -> master [label = "git pull bob", constraint = false]
+    omain -> main [label = "git pull"]
+    main -> omain [label = "git push", constraint = false]
+    amain -> main [label = "git pull alice", constraint = false]
+    bmain -> main [label = "git pull bob", constraint = false]
 }
diff --git a/img/git-remote-solo.dot b/img/git-remote-solo.dot
index f221ad50a545236277dc727749c9af14feb7f90b..0b3b368cd732a0bf9606a23efac475276a549e1d 100644
--- a/img/git-remote-solo.dot
+++ b/img/git-remote-solo.dot
@@ -9,7 +9,7 @@ digraph {
 
         node [color = orchid]
 
-        omaster[label = "master"]
+        omain[label = "main"]
     }
 
     subgraph clusterlocal {
@@ -17,10 +17,10 @@ digraph {
 
         node [color = orchid]
 
-        master[label = "master"]
+        main[label = "main"]
     }
 
-    omaster -> master [label = "git fetch", style = dotted, ltail = clusterorigin, lhead = clusterlocal]
-    master -> omaster [label = "git push"]
-    omaster -> master [label = "git pull"]
+    omain -> main [label = "git fetch", style = dotted, ltail = clusterorigin, lhead = clusterlocal]
+    main -> omain [label = "git push"]
+    omain -> main [label = "git pull"]
 }
diff --git a/img/motivation-throwaway-playground.dot b/img/motivation-throwaway-playground.dot
index 8fc4cdbd8c4f5335346b8d17cc52611d1e6e6680..d6d1989a7f6a99a5f87c4c169141b27a32d519bd 100644
--- a/img/motivation-throwaway-playground.dot
+++ b/img/motivation-throwaway-playground.dot
@@ -1,16 +1,16 @@
 digraph {
     node [shape = "box", style = "filled, rounded"]
 
-    subgraph clustermaster {
-        label = "master"
+    subgraph clustermain {
+        label = "main"
 
         node [color = limegreen]
 
-        master3[label = "..."]
-        master2[label = "..."]
-        master1[label = "..."]
+        main3[label = "..."]
+        main2[label = "..."]
+        main1[label = "..."]
 
-        master3 -> master2 -> master1
+        main3 -> main2 -> main1
     }
 
     subgraph clusterplayground {
@@ -24,5 +24,5 @@ digraph {
         playground2 -> playground1
     }
 
-    playground1 -> master2
+    playground1 -> main2
 }