Actually handle the include file for "make install"
diff --git a/MCONFIG b/MCONFIG
index 9771ba9..06813e4 100644
--- a/MCONFIG
+++ b/MCONFIG
@@ -23,3 +23,4 @@
 prefix	     = /usr/local
 libdir	     = $(prefix)/lib
 mandir	     = $(prefix)/man
+includedir   = $(prefix)/include
diff --git a/Makefile b/Makefile
index fd53cda..1d25df2 100644
--- a/Makefile
+++ b/Makefile
@@ -61,8 +61,8 @@
 install: all
 	mkdir -p $(INSTALLROOT)$(libdir)
 	$(INSTALL_LIB) $(LIB_FILE) $(SO_FILE) $(SO_NAME) $(INSTALLROOT)$(libdir)
-	mkdir -p $(INSTALLROOT)$(installdir)
-	$(INSTALL_DATA) ucd.h $(INSTALLROOT)$(installdir)
+	mkdir -p $(INSTALLROOT)$(includedir)
+	$(INSTALL_DATA) ucd.h $(INSTALLROOT)$(includedir)
 	mkdir -p $(INSTALLROOT)$(mandir)/man3
 	$(INSTALL_DATA) *.3 $(INSTALLROOT)$(mandir)/man3