diff --git a/prjxray/util.py b/prjxray/util.py
index 35603fc9..09377c83 100644
--- a/prjxray/util.py
+++ b/prjxray/util.py
@@ -74,19 +74,23 @@ def db_root_arg(parser):
 
 
 def parse_db_line(line):
+    '''Return tag name, bit values (if any), mode (if any)'''
     parts = line.split()
     # Ex: CLBLL_L.SLICEL_X0.AMUX.A5Q
     assert len(parts), "Empty line"
     tag = parts[0]
+    if tag == 'bit':
+        raise ValueError("Wanted bits db but got mask db")
     assert re.match(r'[A-Z0-9_.]+',
                     tag), "Invalid tag name: %s, line: %s" % (tag, line)
     orig_bits = line.replace(tag + " ", "")
     # <0 candidates> etc
-    if "<" in orig_bits:
-        return tag, set(), orig_bits
+    # Ex: INT_L.BYP_BOUNCE5.BYP_ALT5 always
+    if "<" in orig_bits or "always" == orig_bits:
+        return tag, None, orig_bits
 
-    # Ex: !30_06 !30_08 !30_11 30_07
     bits = frozenset(parts[1:])
+    # Ex: CLBLL_L.SLICEL_X0.AOUTMUX.A5Q !30_06 !30_08 !30_11 30_07
     for bit in bits:
         # 19_39
         # 100_319
diff --git a/utils/dbfixup.py b/utils/dbfixup.py
index 758d5592..094629aa 100755
--- a/utils/dbfixup.py
+++ b/utils/dbfixup.py
@@ -124,19 +124,24 @@ def add_zero_bits(fn_in, fn_out, zero_db, clb_int=False, verbose=False):
             assert mode not in (
                 "<const0>",
                 "<const1>"), "Entries must be resolved. line: %s" % (line, )
-            if mode:
-                assert mode == "<0 candidates>"
-            """
-            This appears to be a large range of one hot interconnect bits
-            They are immediately before the first CLB real bits
-            """
-            if clb_int:
-                zero_range(bits, 22, 25)
-            bits = set(bits)
-            zero_groups(
-                tag, bits, zero_db, strict=not clb_int, verbose=verbose)
 
-            new_line = " ".join([tag] + sorted(bits))
+            if mode == "always":
+                new_line = line
+            elif mode == "<0 candidates>":
+                """
+                This appears to be a large range of one hot interconnect bits
+                They are immediately before the first CLB real bits
+                """
+                if clb_int:
+                    zero_range(bits, 22, 25)
+                bits = set(bits)
+                zero_groups(
+                    tag, bits, zero_db, strict=not clb_int, verbose=verbose)
+
+                new_line = " ".join([tag] + sorted(bits))
+            else:
+                assert 0, line
+
             if new_line != line:
                 changes += 1
             new_lines.add(new_line)
diff --git a/utils/mergedb.sh b/utils/mergedb.sh
index 848d50f3..90aca2b0 100755
--- a/utils/mergedb.sh
+++ b/utils/mergedb.sh
@@ -10,6 +10,13 @@ test -e "$2"
 tmp1=`mktemp -p .`
 tmp2=`mktemp -p .`
 
+function finish {
+    echo "Cleaning up temp files"
+    rm -f "$tmp1"
+    rm -f "$tmp2"
+}
+trap finish EXIT
+
 db=$XRAY_DATABASE_DIR/$XRAY_DATABASE/segbits_$1.db
 
 # Fuzzers verify L/R data is equivilent
@@ -72,5 +79,4 @@ esac
 touch "$db"
 sort -u "$tmp1" "$db" | grep -v '<.*>' > "$tmp2" || true
 ${XRAY_PARSEDB} --strict "$tmp2" "$db"
-rm -f "$tmp1"
 
diff --git a/utils/parsedb.py b/utils/parsedb.py
index e3837798..b24ad42f 100755
--- a/utils/parsedb.py
+++ b/utils/parsedb.py
@@ -5,21 +5,28 @@ from prjxray import util
 
 def run(fnin, fnout=None, strict=False, verbose=False):
     lines = open(fnin, 'r').read().split('\n')
-    tags = set()
+    tags = dict()
     bitss = set()
     for line in lines:
         line = line.strip()
         if line == '':
             continue
+        # TODO: figure out what to do with masks
+        if line.startswith("bit "):
+            continue
         tag, bits, mode = util.parse_db_line(line)
         if strict:
-            assert not mode, "strict: got ill defined line: %s" % (line, )
-            assert tag not in tags, "strict: got duplicate tag %s (ex: %s)" % (
-                tag, line)
+            if mode != "always":
+                assert not mode, "strict: got ill defined line: %s" % (line, )
+            if tag in tags:
+                print("Original line: %s" % tags[tag])
+                print("New line: %s" % line)
+                assert 0, "strict: got duplicate tag %s" % (tag, )
             assert bits not in bitss, "strict: got duplicate bits %s (ex: %s)" % (
                 bits, line)
-        tags.add(tag)
-        bitss.add(bits)
+        tags[tag] = line
+        if bits != None:
+            bitss.add(bits)
 
     if fnout:
         with open(fnout, "w") as fout: