diff --git a/scripts/dbgbmap.py b/scripts/dbgbmap.py
index 633b2e4e..ad444290 100755
--- a/scripts/dbgbmap.py
+++ b/scripts/dbgbmap.py
@@ -2778,7 +2778,8 @@ class Gstate:
             block, trunk, cksum, d_ = frombranch(self.data, d); d += d_
             self.btree = Btree.fetchck(
                     mtree.bd, block, trunk,
-                    config.geometry.block_count,
+                    config.geometry.block_count
+                        if config.geometry is not None else 0,
                     cksum)
 
         def repr(self):
diff --git a/scripts/dbgbmapsvg.py b/scripts/dbgbmapsvg.py
index 3e522454..5aafc017 100755
--- a/scripts/dbgbmapsvg.py
+++ b/scripts/dbgbmapsvg.py
@@ -2808,7 +2808,8 @@ class Gstate:
             block, trunk, cksum, d_ = frombranch(self.data, d); d += d_
             self.btree = Btree.fetchck(
                     mtree.bd, block, trunk,
-                    config.geometry.block_count,
+                    config.geometry.block_count
+                        if config.geometry is not None else 0,
                     cksum)
 
         def repr(self):
diff --git a/scripts/dbglfs3.py b/scripts/dbglfs3.py
index 5af36289..055a4609 100755
--- a/scripts/dbglfs3.py
+++ b/scripts/dbglfs3.py
@@ -2735,7 +2735,8 @@ class Gstate:
             block, trunk, cksum, d_ = frombranch(self.data, d); d += d_
             self.btree = Btree.fetchck(
                     mtree.bd, block, trunk,
-                    config.geometry.block_count,
+                    config.geometry.block_count
+                        if config.geometry is not None else 0,
                     cksum)
 
         def repr(self):