diff --git a/database/Makefile b/database/Makefile
index 082ade76..32df51c8 100644
--- a/database/Makefile
+++ b/database/Makefile
@@ -1,14 +1,18 @@
 
 DATABASE_FILES = *.csv *.db *.json *.yaml
+TIMINGS_FILES = *.sdf
 
 clean-artix7-db:
 	rm -f $(addprefix artix7/,$(DATABASE_FILES))
+	rm -f $(addprefix artix7/timings/,$(TIMINGS_FILES))
 
 clean-kintex7-db:
 	rm -f $(addprefix kintex7/,$(DATABASE_FILES))
+	rm -f $(addprefix kintex7/timings/,$(TIMINGS_FILES))
 
 clean-zynq7-db:
 	rm -f $(addprefix zynq7/,$(DATABASE_FILES))
+	rm -f $(addprefix zynq7/timings/,$(TIMINGS_FILES))
 
 clean-db: clean-artix7-db clean-kintex7-db clean-zynq7-db
 	@true
diff --git a/fuzzers/007-timing/bel/tim2json.py b/fuzzers/007-timing/bel/tim2json.py
index e9af718f..002d8805 100644
--- a/fuzzers/007-timing/bel/tim2json.py
+++ b/fuzzers/007-timing/bel/tim2json.py
@@ -97,7 +97,6 @@ def read_raw_timings(fin, properties, pins, site_pins):
 
             sites_count = int(raw_data[1])
             loc = 2
-            timings[slice] = dict()
             for site in range(0, sites_count):
 
                 site_name = raw_data[loc]
@@ -275,6 +274,9 @@ def read_raw_timings(fin, properties, pins, site_pins):
                         delay_btype = speed_model
                         extra_ports = None
 
+                        if slice not in timings:
+                            timings[slice] = dict()
+
                         if bel_location not in timings[slice]:
                             timings[slice][bel_location] = dict()