diff --git a/Makefile b/Makefile
index 94bea145..7f37aed9 100644
--- a/Makefile
+++ b/Makefile
@@ -83,9 +83,7 @@ all: +all README.md
 binaries: all
 tests: all
 	
-# No $(EXT) here, even on Windows, as this program isn't exported
-# outside WSL.
-README.md: $(OBJ)/scripts/+mkdocindex/mkdocindex
+README.md: $(OBJ)/scripts/+mkdocindex/mkdocindex$(EXT)
 	@echo $(PROGRESSINFO)MKDOC $@
 	@csplit -s -f$(OBJ)/README. README.md '/<!-- FORMATSSTART -->/' '%<!-- FORMATSEND -->%'
 	@(cat $(OBJ)/README.00 && $< && cat $(OBJ)/README.01) > README.md
diff --git a/build.py b/build.py
index 3b543cfe..de13a623 100644
--- a/build.py
+++ b/build.py
@@ -7,6 +7,11 @@ from glob import glob
 import config
 import re
 
+# Hack for building on Fedora/WSL; executables get the .exe extension,
+# build the build system detects it as Linux.
+import build.toolchain
+toolchain.Toolchain.EXE = "$(EXT)"
+
 package(name="protobuf_lib", package="protobuf")
 package(name="z_lib", package="zlib")
 package(name="fmt_lib", package="fmt", fallback="dep/fmt")