Index: Printing/GSCUPS/GNUmakefile.preamble
===================================================================
--- Printing/GSCUPS/GNUmakefile.preamble	(revision 37046)
+++ Printing/GSCUPS/GNUmakefile.preamble	(working copy)
@@ -21,7 +21,7 @@
 ADDITIONAL_LDFLAGS += $(GSCUPS_LDFLAGS)
 
 # Additional library directories the linker should search
-ADDITIONAL_LIB_DIRS += -L../../Source/$(GNUSTEP_OBJ_DIR)
+ADDITIONAL_LIB_DIRS := -L../../Source/$(GNUSTEP_OBJ_DIR) $(ADDITIONAL_LIB_DIRS)
 
 # Additional libraries
 
Index: Printing/GSLPR/GNUmakefile.preamble
===================================================================
--- Printing/GSLPR/GNUmakefile.preamble	(revision 37046)
+++ Printing/GSLPR/GNUmakefile.preamble	(working copy)
@@ -21,7 +21,7 @@
 ADDITIONAL_LDFLAGS += 
 
 # Additional library directories the linker should search
-ADDITIONAL_LIB_DIRS += -L../../Source/$(GNUSTEP_OBJ_DIR)
+ADDITIONAL_LIB_DIRS := -L../../Source/$(GNUSTEP_OBJ_DIR) $(ADDITIONAL_LIB_DIRS)
 
 # Additional libraries
 
Index: Tools/GNUmakefile.preamble
===================================================================
--- Tools/GNUmakefile.preamble	(revision 37046)
+++ Tools/GNUmakefile.preamble	(working copy)
@@ -29,7 +29,7 @@
 # ADDITIONAL_LDFLAGS +=
 
 # Additional library directories the linker should search
-ADDITIONAL_LIB_DIRS += -L../Source/$(GNUSTEP_OBJ_DIR) -L../Model/$(GNUSTEP_OBJ_DIR)
+ADDITIONAL_LIB_DIRS := -L../Source/$(GNUSTEP_OBJ_DIR) -L../Model/$(GNUSTEP_OBJ_DIR) $(ADDITIONAL_LIB_DIRS)
 
 # Additional libraries when linking tools
 gpbs_TOOL_LIBS += -lgnustep-gui $(SYSTEM_LIBS)