diff --git a/fuzzers/005-tilegrid/Makefile b/fuzzers/005-tilegrid/Makefile
index 3ff18819..1ddca0ab 100644
--- a/fuzzers/005-tilegrid/Makefile
+++ b/fuzzers/005-tilegrid/Makefile
@@ -11,8 +11,9 @@ pushdb:
 build/tiles/tiles.txt:
 	bash generate.sh build/tiles tiles
 
-build/tilegrid_basic.json: generate.py build/tiles/tiles.txt
-	cd build && python3 ${FUZDIR}/generate.py --tiles $(FUZDIR)/build/tiles/tiles.txt --out ${BUILD_DIR}/tilegrid_basic.json
+build/basicdb/tilegrid.json: generate.py build/tiles/tiles.txt
+	mkdir -p build/basicdb
+	cd build && python3 ${FUZDIR}/generate.py --tiles $(FUZDIR)/build/tiles/tiles.txt --out ${BUILD_DIR}/basicdb/tilegrid.json
 
 build/clb/deltas:
 	bash generate.sh build/clb clb
@@ -25,9 +26,9 @@ build/iob/deltas:
 	bash generate.sh build/iob iob
 
 build/tilegrid_tdb.json: iob/build/segbits_tilegrid.tdb
-	python3 add_tdb.py --fn-in build/tilegrid_basic.json --fn-out build/tilegrid_tdb.json
+	python3 add_tdb.py --fn-in build/basicdb/tilegrid.json --fn-out build/tilegrid_tdb.json
 
-iob/build/segbits_tilegrid.tdb: build/tilegrid_basic.json
+iob/build/segbits_tilegrid.tdb: build/basicdb/tilegrid.json
 	cd iob && $(MAKE)
 
 # FIXME: review IOB
@@ -44,6 +45,7 @@ run:
 
 clean:
 	rm -rf build
+	cd iob && $(MAKE) clean
 
 .PHONY: database pushdb clean run
 
diff --git a/fuzzers/005-tilegrid/iob/generate.sh b/fuzzers/005-tilegrid/iob/generate.sh
index 7d49e204..e66d1317 100644
--- a/fuzzers/005-tilegrid/iob/generate.sh
+++ b/fuzzers/005-tilegrid/iob/generate.sh
@@ -7,7 +7,7 @@ source ${XRAY_GENHEADER}
 
 # Some projects have hard coded top.v, others are generated
 if [ -f $FUZDIR/top.py ] ; then
-    python3 $FUZDIR/top.py >top.v
+    XRAY_DATABASE_ROOT=$FUZDIR/../build/basicdb python3 $FUZDIR/top.py >top.v
 fi
 
 vivado -mode batch -source $FUZDIR/generate.tcl
diff --git a/prjxray/util.py b/prjxray/util.py
index 8329f496..dec5e82d 100644
--- a/prjxray/util.py
+++ b/prjxray/util.py
@@ -5,6 +5,11 @@ from .db import Database
 
 
 def get_db_root():
+    # Used during tilegrid db bootstrap
+    ret = os.getenv("XRAY_DATABASE_ROOT", None)
+    if ret:
+        return ret
+
     return "%s/%s" % (
         os.getenv("XRAY_DATABASE_DIR"), os.getenv("XRAY_DATABASE"))