diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
index 1830ef5309fe..7c1db6be21c0 100644
--- a/lib/matplotlib/axes/_axes.py
+++ b/lib/matplotlib/axes/_axes.py
@@ -2057,9 +2057,9 @@ def _convert_dx(dx, x0, xconv, convert):
             dx = [convert(x0 + ddx) - x for ddx in dx]
             if delist:
                 dx = dx[0]
-        except (TypeError, AttributeError) as e:
-            # but doesn't work for 'string' + float, so just
-            # see if the converter works on the float.
+        except (ValueError, TypeError, AttributeError):
+            # if the above fails (for any reason) just fallback to what
+            # we do by default and convert dx by iteslf.
             dx = convert(dx)
         return dx