--- postgresql-10.0/src/pl/tcl/Makefile.orig	2017-10-02 16:09:15.000000000 -0500
+++ postgresql-10.0/src/pl/tcl/Makefile	2017-11-04 13:50:43.945313037 -0500
@@ -16,6 +16,10 @@
 # On Windows, we don't link directly with the Tcl library; see below
 ifneq ($(PORTNAME), win32)
 SHLIB_LINK = $(TCL_LIB_SPEC) $(TCL_LIBS) -lc
+else
+ifeq ($(host_os), mingw32)
+SHLIB_LINK = $(TCL_LIB_SPEC) $(TCL_LIBS)
+endif
 endif
 
 PGFILEDESC = "PL/Tcl - procedural language"
@@ -34,6 +38,7 @@
 # which are not compatible with mingw gcc. Therefore we need to build a
 # new import library to link with.
 ifeq ($(PORTNAME), win32)
+ifneq ($(host_os), mingw32)
 
 tclwithver = $(subst -l,,$(filter -l%, $(TCL_LIB_SPEC)))
 TCLDLL = $(dir $(TCLSH))/$(tclwithver).dll
@@ -46,6 +51,7 @@
 $(tclwithver).def: $(TCLDLL)
 	pexports $^ > $@
 
+endif # mingw32
 endif # win32
 
 
@@ -94,8 +100,10 @@
 	rm -f $(OBJS)
 	rm -rf $(pg_regress_clean_files)
 ifeq ($(PORTNAME), win32)
+ifneq ($(host_os), mingw32)
 	rm -f $(tclwithver).def
 endif
+endif
 
 maintainer-clean: distclean
 	rm -f pltclerrcodes.h