4 files changed, 4 insertions, 4 deletions
diff --git a/c/src/libnetworking/rtems/Makefile.am b/c/src/libnetworking/rtems/Makefile.am
index 47846d1c4f..06e57fa081 100644
--- a/c/src/libnetworking/rtems/Makefile.am
+++ b/c/src/libnetworking/rtems/Makefile.am
@@ -21,7 +21,7 @@ OBJS = $(C_O_FILES)
 
 include_rtems_HEADERS = rtems_bsdnet.h rtems_bsdnet_internal.h tftp.h
 
-PREINSTALL_FILES += $(PROJECT_INCLUDE)/rtems \
+PREINSTALL_FILES = $(PROJECT_INCLUDE)/rtems \
     $(include_rtems_HEADERS:%=$(PROJECT_INCLUDE)/rtems/%)
 
 $(PROJECT_INCLUDE)/rtems:
diff --git a/c/src/libnetworking/rtems_servers/Makefile.am b/c/src/libnetworking/rtems_servers/Makefile.am
index 17ad1c5fcb..5c606c7835 100644
--- a/c/src/libnetworking/rtems_servers/Makefile.am
+++ b/c/src/libnetworking/rtems_servers/Makefile.am
@@ -35,7 +35,7 @@ include_HEADERS = ftpd.h
 
 include_rtems_HEADERS =
 
-PREINSTALL_FILES += $(PROJECT_INCLUDE) \
+PREINSTALL_FILES = $(PROJECT_INCLUDE) \
    $(include_HEADERS:%=$(PROJECT_INCLUDE)/%) \
    $(include_rtems_HEADERS:%=$(PROJECT_INCLUDE)/rtems/%)
 
diff --git a/c/src/libnetworking/rtems_telnetd/Makefile.am b/c/src/libnetworking/rtems_telnetd/Makefile.am
index a5d0480722..f3c3ac0020 100644
--- a/c/src/libnetworking/rtems_telnetd/Makefile.am
+++ b/c/src/libnetworking/rtems_telnetd/Makefile.am
@@ -32,7 +32,7 @@ $(PROJECT_INCLUDE)/rtems/%.h: %.h
 $(LIB): $(OBJS)
 	$(make-library)
 
-PREINSTALL_FILES += $(PROJECT_INCLUDE)/rtems \
+PREINSTALL_FILES = $(PROJECT_INCLUDE)/rtems \
     $(include_rtems_HEADERS:%=$(PROJECT_INCLUDE)/rtems/%)
 
 all-local: $(ARCH) $(PREINSTALL_FILES) $(OBJS) $(LIB)
diff --git a/c/src/libnetworking/rtems_webserver/Makefile.am b/c/src/libnetworking/rtems_webserver/Makefile.am
index 1cbb77b00d..c942a5c085 100644
--- a/c/src/libnetworking/rtems_webserver/Makefile.am
+++ b/c/src/libnetworking/rtems_webserver/Makefile.am
@@ -44,7 +44,7 @@ $(PROJECT_INCLUDE)/goahead/%.h: %.h
 $(PROJECT_INCLUDE)/rtems_webserver.h: rtems_webserver.h
 	$(INSTALL_DATA) $< $@
 
-PREINSTALL_FILES += $(PROJECT_INCLUDE) $(PROJECT_INCLUDE)/rtems_webserver.h \
+PREINSTALL_FILES = $(PROJECT_INCLUDE) $(PROJECT_INCLUDE)/rtems_webserver.h \
     $(PROJECT_INCLUDE)/goahead $(H_FILES:%.h=$(PROJECT_INCLUDE)/goahead/%.h)
 
 if HAS_POSIX