diff --git a/.editorconfig b/.editorconfig
index 39320ba..3dd05d3 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -11,7 +11,10 @@
 insert_final_newline = true
 trim_trailing_whitespace = true
 
-# Makefile
+[imstb_*]
+indent_size = 3
+trim_trailing_whitespace = false
+
 [Makefile]
 indent_style = tab
 indent_size = 4