diff --git a/CHANGELOG.md b/CHANGELOG.md
index b803b6d..2abd344 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ this project uses date-based 'snapshot' version identifiers.
 - Extend version string normalisation during checks
   (see issue \#96)
 
+- Extend excludefiles to cover `build.lua` (see \#286)
 ### Fixed
 - Return passing errorlevel if BibTeX issues warnings
   (see \#260)
diff --git a/l3build-variables.lua b/l3build-variables.lua
index 204c386..bbebf2f 100644
--- a/l3build-variables.lua
+++ b/l3build-variables.lua
@@ -83,7 +83,7 @@ cleanfiles         = cleanfiles         or {"*.log", "*.pdf", "*.zip"}
 demofiles          = demofiles          or { }
 docfiles           = docfiles           or { }
 dynamicfiles       = dynamicfiles       or { }
-excludefiles       = excludefiles       or {"*~"}
+excludefiles       = excludefiles       or {"*~","build.lua","config-*.lua"}
 exefiles           = exefiles           or { }
 installfiles       = installfiles       or {"*.sty","*.cls"}
 makeindexfiles     = makeindexfiles     or {"*.ist"}
diff --git a/l3build.dtx b/l3build.dtx
index d138ea7..295e270 100644
--- a/l3build.dtx
+++ b/l3build.dtx
@@ -88,7 +88,7 @@
 \luavarset{demofiles}         {\{\}}{Files which show how to use a module}
 \luavarset{docfiles}          {\{\}}{Files which are part of the documentation but should not be typeset}
 \luavarset{dynamicfiles}      {\{ \}}{Secondary files to cleared before each test is run}
-\luavarset{excludefiles}      {\{"*\string~"\}}{Files to ignore entirely (default for Emacs backup files)}
+\luavarset{excludefiles}      {\{"*\string~","build.lua","config-*.lua"\}}{Files to ignore entirely (default for Emacs backup files)}
 \luavarset{installfiles}      {\{"*.sty","*.cls"\}}{Files to install to the \texttt{tex} area of the \texttt{texmf} tree}
 \luavarset{makeindexfiles}    {\{"*.ist"\}}{MakeIndex files to be included in a TDS-style zip}
 \luavarset{scriptfiles}       {\{ \}}{Files to install to the \texttt{scripts} area of the \texttt{texmf} tree}