diff --git a/graphene/relay/mutation.py b/graphene/relay/mutation.py
index 8c020ef0..2f6d1ce5 100644
--- a/graphene/relay/mutation.py
+++ b/graphene/relay/mutation.py
@@ -59,7 +59,7 @@ class ClientIDMutation(Mutation):
         def on_resolve(payload):
             try:
                 payload.client_mutation_id = input.get('client_mutation_id')
-            except:
+            except Exception:
                 raise Exception(
                     ('Cannot set client_mutation_id in the payload object {}'
                      ).format(repr(payload)))
diff --git a/graphene/relay/node.py b/graphene/relay/node.py
index 4cb51cfc..6596757c 100644
--- a/graphene/relay/node.py
+++ b/graphene/relay/node.py
@@ -96,7 +96,7 @@ class Node(AbstractNode):
         try:
             _type, _id = cls.from_global_id(global_id)
             graphene_type = info.schema.get_type(_type).graphene_type
-        except:
+        except Exception:
             return None
 
         if only_type:
diff --git a/graphene/types/datetime.py b/graphene/types/datetime.py
index 0a0e3343..b11671f9 100644
--- a/graphene/types/datetime.py
+++ b/graphene/types/datetime.py
@@ -8,7 +8,7 @@ from .scalars import Scalar
 
 try:
     import iso8601
-except:
+except ImportError:
     raise ImportError(
         "iso8601 package is required for DateTime Scalar.\n"
         "You can install it using: pip install iso8601."