ifeq "$(INSTALLING)$(HOSTPLATFORM)" "0i386-unknown-mingw32"
all :: $(INPLACE_SCRIPT_PROG).bat
-FULL_INPLACE_PATH=$(subst /,\\,$(FPTOOLS_TOP_ABS)/utils/hsc2hs/)
+# See "MSys Note 3" in compiler/Makefile
+FULL_INPLACE_PATH=$(subst /,\,$(FPTOOLS_TOP_ABS_PLATFORM)/utils/hsc2hs/)
$(INPLACE_SCRIPT_PROG).bat :
echo '@call $(FULL_INPLACE_PATH)$(HS_PROG) --template=$(FULL_INPLACE_PATH)template-hsc.h $(HSC2HS_EXTRA) %*' >> $@
chmod 755 $@