diff --git a/Make.sysdefs b/Make.sysdefs
index fc044e14..a6f2a8e0 100644
--- a/Make.sysdefs
+++ b/Make.sysdefs
@@ -52,6 +52,10 @@ NTCFLAGS = /D_WIN32 /Od /G3 /Zp2 /nologo /MT
 NTLFLAGS =
 NTMASTER = CC=CL GLOBALCFLAGS="$(NTCFLAGS)" GLOBALLFLAGS="$(NTLFLAGS)"
 
+INTERIXCFLAGS = -g -fno-common -D_EMPTH_POSIX=1 -U_EMPTH_LWP -DLISTENMAXCONN=5 -DRel4 -D_ALL_SOURCE $(GCCWARNFLAGS)
+INTERIXLFLAGS = -lpthread
+INTERIXMASTER = GLOBALCFLAGS="$(INTERIXCFLAGS)" GLOBALLFLAGS="$(INTERIXLFLAGS)" CLIENTLIBS=-lncurses
+
 NEXTCFLAGS = -bsd -fwritable-strings -traditional -Dconst="" -Dinline=""
 NEXTLFLAGS = -lsys_s
 NEXTMASTER = GLOBALCFLAGS="$(NEXTCFLAGS)" GLOBALLFLAGS="$(NEXTLFLAGS)"
diff --git a/Makefile b/Makefile
index 49ef73bb..2d3e8e30 100644
--- a/Makefile
+++ b/Makefile
@@ -53,6 +53,7 @@ all:
 	@echo '   freebsd'
 	@echo '   hp'
 	@echo '   hpux'
+	@echo '   interix'
 	@echo '   irix'
 	@echo '   irix5'
 	@echo '   isi'
@@ -224,6 +225,14 @@ nt:
 	$(MAKE) ntbinaries TOBUILD=nt $(NTMASTER)
 	$(MAKE) ntinstall
 
+interix:
+	@echo 'building a $(WORLDX) by $(WORLDY) server...'
+	(cd src/doconfig; $(MAKE) $(INTERIXMASTER))
+	($(MAKE) genlibs $(INTERIXMASTER))
+	(cd src/lib/lwp; $(MAKE) $(INTERIXMASTER))
+	($(MAKE) binaries $(INTERIXMASTER))
+	($(MAKE) install)
+
 vaxultrix:
 	@echo 'building a $(WORLDX) by $(WORLDY) server...'
 	(cd src/doconfig; $(MAKE) $(VAXULTMASTER))