diff --git a/.gitignore b/.gitignore
index 7b813178d..e18133eb9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -46,6 +46,7 @@ tools-for-build/determine-endianness
 tools-for-build/determine-endianness.exe
 tools-for-build/grovel-headers
 tools-for-build/grovel-headers.exe
+tools-for-build/mmap-rwx
 tools-for-build/os-provides-putwc-test
 tools-for-build/os-provides-putwc-test.exe
 tools-for-build/where-is-mcontext
diff --git a/tools-for-build/Makefile b/tools-for-build/Makefile
index 3f6e4ecf9..1be91e9df 100644
--- a/tools-for-build/Makefile
+++ b/tools-for-build/Makefile
@@ -14,8 +14,8 @@ CPPFLAGS+=-I../src/runtime
 LDFLAGS:=$(LDFLAGS)
 LDLIBS:=$(OS_LIBS)
 
-all: grovel-headers determine-endianness where-is-mcontext
+all: grovel-headers determine-endianness where-is-mcontext mmap-rwx
 
 clean:
-	rm -f *.o grovel-headers determine-endianness where-is-mcontext
+	rm -f *.o grovel-headers determine-endianness where-is-mcontext mmap-rwx
 	rm -f *.exe