diff --git a/cmk/base/check_legacy_includes/df.py b/cmk/base/check_legacy_includes/df.py
index 2ac811c5222..d139a91fdf4 100644
--- a/cmk/base/check_legacy_includes/df.py
+++ b/cmk/base/check_legacy_includes/df.py
@@ -137,9 +137,9 @@ def df_check_filesystem_single_coroutine(  # pylint: disable=too-many-branches
             params.get("subtract_reserved", False) and reserved_mb > 0,
             params.get("show_reserved") and reserved_mb > 0,
         )
-        # params might still be a tuple
+        # params might still be a tuple  # (mo): I don't think so.
         if isinstance(params, dict)
-        else (False, False, False)
+        else ("onproblem", False, False)
     )
 
     used_mb = size_mb - avail_mb
diff --git a/cmk/base/legacy_checks/hp_blade_blades.py b/cmk/base/legacy_checks/hp_blade_blades.py
index 0b061d3613e..135c8735268 100644
--- a/cmk/base/legacy_checks/hp_blade_blades.py
+++ b/cmk/base/legacy_checks/hp_blade_blades.py
@@ -41,7 +41,7 @@
 }
 
 
-def saveint(i: str) -> int:
+def saveint(i: object) -> int:
     """Tries to cast a string to an integer and return it. In case this
     fails, it returns 0.
 
@@ -49,7 +49,7 @@ def saveint(i: str) -> int:
     bad style these days, because in case you get 0 back from this function,
     you can not know whether it is really 0 or something went wrong."""
     try:
-        return int(i)
+        return int(i)  # type: ignore[call-overload]
     except (TypeError, ValueError):
         return 0
 
diff --git a/cmk/plugins/mysql/agent_based/mysql_replica_slave.py b/cmk/plugins/mysql/agent_based/mysql_replica_slave.py
index 4080bda714a..fcb63aa1a31 100644
--- a/cmk/plugins/mysql/agent_based/mysql_replica_slave.py
+++ b/cmk/plugins/mysql/agent_based/mysql_replica_slave.py
@@ -32,7 +32,7 @@ class Error(NamedTuple):
     message: str
 
 
-Section = Error | dict[str, int | None | bool | Literal["NULL"]]
+Section = Error | Mapping[str, int | None | bool | Literal["NULL"]]
 
 
 def _parse_mysql_replica_slave(