diff --git a/en_US.ISO8859-1/htdocs/releases/12.0R/errata/Makefile b/en_US.ISO8859-1/htdocs/releases/12.0R/errata/Makefile
index b0815a0391..37b8144030 100644
--- a/en_US.ISO8859-1/htdocs/releases/12.0R/errata/Makefile
+++ b/en_US.ISO8859-1/htdocs/releases/12.0R/errata/Makefile
@@ -21,6 +21,13 @@ SRCS?=			errata.xml
 
 DATA+=			${DOC}.html
 
+beforeclean:
+CLEANFILES+=		${DOC}.html \
+			${DOC}.txt \
+			catalog-cwd.xml \
+			autogen.ent \
+			${DOC}.parsed.*
+
 install: ${DOC}.html
 	mkdir -p ${DOCINSTALLDIR}
 	${INSTALL_DOCS} ${DATA} ${DOCINSTALLDIR}
diff --git a/en_US.ISO8859-1/htdocs/releases/12.0R/hardware/Makefile b/en_US.ISO8859-1/htdocs/releases/12.0R/hardware/Makefile
index 56d68904f2..bfaeab5665 100644
--- a/en_US.ISO8859-1/htdocs/releases/12.0R/hardware/Makefile
+++ b/en_US.ISO8859-1/htdocs/releases/12.0R/hardware/Makefile
@@ -21,6 +21,13 @@ SRCS?=			hardware.xml
 
 DATA+=			${DOC}.html
 
+beforeclean:
+CLEANFILES+=		${DOC}.html \
+			${DOC}.txt \
+			catalog-cwd.xml \
+			autogen.ent \
+			${DOC}.parsed.*
+
 install: ${DOC}.html
 	mkdir -p ${DOCINSTALLDIR}
 	${INSTALL_DOCS} ${DATA} ${DOCINSTALLDIR}
diff --git a/en_US.ISO8859-1/htdocs/releases/12.0R/readme/Makefile b/en_US.ISO8859-1/htdocs/releases/12.0R/readme/Makefile
index 83c15c50ac..3296148140 100644
--- a/en_US.ISO8859-1/htdocs/releases/12.0R/readme/Makefile
+++ b/en_US.ISO8859-1/htdocs/releases/12.0R/readme/Makefile
@@ -21,6 +21,13 @@ SRCS?=			readme.xml
 
 DATA+=			${DOC}.html
 
+beforeclean:
+CLEANFILES+=		${DOC}.html \
+			${DOC}.txt \
+			catalog-cwd.xml \
+			autogen.ent \
+			${DOC}.parsed.*
+
 install: ${DOC}.html
 	mkdir -p ${DOCINSTALLDIR}
 	${INSTALL_DOCS} ${DATA} ${DOCINSTALLDIR}
diff --git a/en_US.ISO8859-1/htdocs/releases/12.0R/relnotes/Makefile b/en_US.ISO8859-1/htdocs/releases/12.0R/relnotes/Makefile
index 51e78260ab..4f2942ecd5 100644
--- a/en_US.ISO8859-1/htdocs/releases/12.0R/relnotes/Makefile
+++ b/en_US.ISO8859-1/htdocs/releases/12.0R/relnotes/Makefile
@@ -21,6 +21,13 @@ SRCS?=			relnotes.xml
 
 DATA+=			${DOC}.html
 
+beforeclean:
+CLEANFILES+=		${DOC}.html \
+			${DOC}.txt \
+			catalog-cwd.xml \
+			autogen.ent \
+			${DOC}.parsed.*
+
 install: ${DOC}.html
 	mkdir -p ${DOCINSTALLDIR}
 	${INSTALL_DOCS} ${DATA} ${DOCINSTALLDIR}