diff --git a/ChangeLog b/ChangeLog
index 32f320199a..7316777d55 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2015-09-08  Samuel Thibault  <samuel.thibault@ens-lyon.org>
+
+	Fix parallel build of before-compile targets.
+
+	* sysdeps/mach/Makefile ($(patsubst
+	mach%,m\%h%,$(mach-before-compile))): Move rule to dedicated
+	mach-before-compile target.
+	* sysdeps/mach/hurd/Makefile ($(patsubst %,$(hurd-objpfx)hurd/%.%,auth
+	io fs process)): Move rule to dedicated hurd-before-compile target.
+
 2015-09-06  Samuel Thibault  <samuel.thibault@ens-lyon.org>
 
 	Fix rules generating headers in hurd/ and mach/ when initial make call
diff --git a/sysdeps/mach/Makefile b/sysdeps/mach/Makefile
index 3323e818eb..c6f44fe5fc 100644
--- a/sysdeps/mach/Makefile
+++ b/sysdeps/mach/Makefile
@@ -42,7 +42,9 @@ mach-before-compile := $(mach-objpfx)mach-shortcuts.h \
 ifneq (mach,$(subdir))
 # This patsubst generates patterns like `m%h-shortcuts.h', which are damn
 # likely to match just the corresponding particular file we want.
-$(patsubst mach%,m\%h%,$(mach-before-compile)): # Run only if doesn't exist.
+$(patsubst mach%,m\%h%,$(mach-before-compile)): mach-before-compile # Run only if doesn't exist.
+.PHONY: mach-before-compile
+mach-before-compile:
 	$(MAKE) -C $(..)mach subdir=mach mach-before-compile no_deps=t generating=t
 
 before-compile += $(mach-before-compile)
diff --git a/sysdeps/mach/hurd/Makefile b/sysdeps/mach/hurd/Makefile
index 244ac4ba30..d8db400579 100644
--- a/sysdeps/mach/hurd/Makefile
+++ b/sysdeps/mach/hurd/Makefile
@@ -46,8 +46,9 @@ hurd-objpfx = $(common-objpfx)hurd/
 
 # These are all the generated headers that <hurd.h> includes.
 before-compile += $(patsubst %,$(hurd-objpfx)hurd/%.h,auth io fs process)
-$(patsubst %,$(hurd-objpfx)hurd/%.%,auth io fs process): \
-  $(common-objpfx)mach/mach-shortcuts.h
+$(patsubst %,$(hurd-objpfx)hurd/%.%,auth io fs process): hurd-before-compile \
+.PHONY: hurd-before-compile
+hurd-before-compile: $(common-objpfx)mach/mach-shortcuts.h
 	$(MAKE) -C $(..)hurd subdir=hurd before-compile no_deps=t
 endif