diff --git a/Makefile.amd64 b/Makefile.amd64
index 2df3f576340c4cffef09a53ef2837ff7a26397ce..88ab52debb9eec9de7dd9c11e671d35597739449 100644
--- a/Makefile.amd64
+++ b/Makefile.amd64
@@ -8,8 +8,14 @@ XINCLUDES = -I/usr/include/openmotif
 XLIBDIR  = /usr/lib64/openmotif
 endif
 
-XINCLUDES ?= /usr/X11R6/include
-XLIBDIR  ?= /usr/X11R6/lib64
+# This is the old location, but include it here, just in case 
+ifeq ($(shell if test -d /usr/X11R6/include; then echo yes; fi),yes)
+XINCLUDES = -I/usr/X11R6/include
+XLIBDIR   = /usr/X11R6/lib
+endif
+
+XINCLUDES ?= /usr/include
+XLIBDIR  ?= /usr/lib64
 
 TKLIB=-lXm -lXpm -lXext -lXp
 XTLIB=-lXt
diff --git a/Makefile.linux b/Makefile.linux
index dc28dd11bc9c6da9ca301a8876cfd173ced436bd..92941ff353ea167b12a7e221353a7e50062e9550 100644
--- a/Makefile.linux
+++ b/Makefile.linux
@@ -8,8 +8,14 @@ XINCLUDES = -I/usr/include/openmotif
 XLIBDIR   = /usr/lib/openmotif
 endif
 
-XINCLUDES ?= /usr/X11R6/include
-XLIBDIR   ?= /usr/X11R6/lib
+# This is the old location, but include it here, just in case 
+ifeq ($(shell if test -d /usr/X11R6/include; then echo yes; fi),yes)
+XINCLUDES = -I/usr/X11R6/include
+XLIBDIR   = /usr/X11R6/lib
+endif
+
+XINCLUDES ?= /usr/include
+XLIBDIR   ?= /usr/lib
 
 TKLIB=-lXm -lXpm -lXext -lXp
 XTLIB=-lXt