1 files changed, 7 insertions, 1 deletions

diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index 1c955883cf58..2c6f66dea650 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -28,7 +28,7 @@ PS_METHOD	= $(prefer-db2x)
 
 ###
 # The targets that may be used.
-.PHONY: xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs
+PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs
 
 BOOKS := $(addprefix $(obj)/,$(DOCBOOKS))
 xmldocs: $(BOOKS)
@@ -211,3 +211,9 @@ clean-dirs := $(patsubst %.xml,%,$(DOCBOOKS))
 
 #man put files in man subdir - traverse down
 subdir- := man/
+
+
+# Declare the contents of the .PHONY variable as phony.  We keep that
+# information in a variable se we can use it in if_changed and friends.
+
+.PHONY: $(PHONY)