diff --git a/synthDC/.synopsys_dc.setup b/synthDC/.synopsys_dc.setup
index ac93f6592..ccc0c67c8 100755
--- a/synthDC/.synopsys_dc.setup
+++ b/synthDC/.synopsys_dc.setup
@@ -29,7 +29,6 @@ if {$tech == "sky130"} {
     set TLUPLUS true
     set mw_logic1_net VDD
     set mw_logic0_net VSS
-    set TLU_PDK /home/jstine/TLU+/
     set CAPTABLE $TLU/1p8m/
     set MW_REFERENCE_LIBRARY /home/jstine/MW
     set MW_TECH_FILE tcbn28hpcplusbwp30p140
diff --git a/synthDC/Makefile b/synthDC/Makefile
index 2f505b72f..fbfb459ad 100755
--- a/synthDC/Makefile
+++ b/synthDC/Makefile
@@ -21,6 +21,7 @@ export MAXCORES ?= 1
 export MAXOPT ?= 0
 export DRIVE ?= FLOP
 export USESRAM ?= 1
+export USETOPO ?= 0
 
 time := $(shell date +%F-%H-%M)
 hash := $(shell git rev-parse --short HEAD)
@@ -30,8 +31,6 @@ export SAIFPOWER ?= 0
 OLDCONFIGDIR ?= ${WALLY}/config
 export CONFIGDIR ?= $(OUTPUTDIR)/config
 
-
-
 default:
 	@echo "  Basic synthesis procedure for Wally:"
 	@echo "        Invoke with make synth"
@@ -51,6 +50,18 @@ DIRS = $(DIRS32) $(DIRS64)
 
 configs: $(CONFIG)
 $(CONFIG):
+ifeq ($(USETOPO), 0))
+ifeq ($(TECH), tsmc28psyn))
+	@echo "Bad configuration: you cannot use physical synthesis without tsmc28psyn and usetopo (i.e., -topo)"
+	exit 1
+endif
+endif
+ifeq ($(USETOPO), 1))
+ifneq ($(TECH), tsmc28psyn))
+	@echo "Bad configuration: you cannot use usetopo (i.e., -topo) without tsmc28psyn"
+	exit 1
+endif
+endif
 	@echo $(CONFIG)
 	cp -r $(OLDCONFIGDIR)/shared/*.vh $(CONFIGDIR)
 	cp -r $(OLDCONFIGDIR)/$(CONFIG)/* $(CONFIGDIR)
@@ -124,15 +135,17 @@ mkdirecs:
 	@mkdir -p $(OUTPUTDIR)/mapped
 	@mkdir -p $(OUTPUTDIR)/unmapped
 
-
 synth: mkdirecs configs rundc clean
 
 rundc:
+ifeq ($(USETOPO), 0)
 	dc_shell-xg-t -64bit -f scripts/$(NAME).tcl | tee $(OUTPUTDIR)/$(NAME).out
+else
 	
-rundctopo:
 	dc_shell-xg-t -64bit -topographical_mode -f scripts/$(NAME).tcl | tee $(OUTPUTDIR)/$(NAME).out
-	
+endif
+
+
 clean:
 	rm -rf $(OUTPUTDIR)/hdl
 	rm -rf $(OUTPUTDIR)/WORK
diff --git a/synthDC/wallySynth.py b/synthDC/wallySynth.py
index 876a482d9..d89964c10 100755
--- a/synthDC/wallySynth.py
+++ b/synthDC/wallySynth.py
@@ -40,7 +40,7 @@ if __name__ == '__main__':
     tech = args.tech if args.tech else 'sky90'
     maxopt = int(args.maxopt)
     usesram = int(args.usesram)
-    usetopo = int(args.usetopop)	
+    usetopo = int(args.usetopo)	
     mod = 'orig'
 
     if args.freqsweep: