diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 000000000..1d7d564d5
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,25 @@
+root = true
+
+[*]
+charset = utf-8
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.md]
+indent_size = 2
+indent_style = space
+max_line_length = 100  # Please keep this in sync with bin/lesson_check.py!
+
+[*.r]
+max_line_length = 80
+
+[*.py]
+indent_size = 4
+indent_style = space
+max_line_length = 79
+
+[*.sh]
+end_of_line = lf
+
+[Makefile]
+indent_style = tab
diff --git a/bin/lesson_check.py b/bin/lesson_check.py
index b728dcb92..84c28f37c 100755
--- a/bin/lesson_check.py
+++ b/bin/lesson_check.py
@@ -102,6 +102,7 @@
 }
 
 # How long are lines allowed to be?
+# Please keep this in sync with .editorconfig!
 MAX_LINE_LEN = 100