diff --git a/vdirsyncer/cli/config.py b/vdirsyncer/cli/config.py
index 59e7425d..6e70032f 100644
--- a/vdirsyncer/cli/config.py
+++ b/vdirsyncer/cli/config.py
@@ -60,6 +60,7 @@ def _validate_collections_param(collections):
         raise ValueError("`collections` parameter must be a list or `null`.")
 
     collection_names = set()
+    collection_blacklist = set()
 
     for i, collection in enumerate(collections):
         try:
@@ -87,9 +88,14 @@ def _validate_collections_param(collections):
             if collection_name in collection_names:
                 raise ValueError("Duplicate value.")
             collection_names.add(collection_name)
+
+            if collection[0] == "!":
+                collection_blacklist.add(collection_name[1:])
         except ValueError as e:
             raise ValueError(f"`collections` parameter, position {i}: {str(e)}")
 
+    return collection_blacklist
+
 
 class _ConfigReader:
     def __init__(self, f):
@@ -233,7 +239,7 @@ def __init__(self, full_config, name, options):
                 "Set `collections = null` explicitly in your pair config."
             )
         else:
-            _validate_collections_param(self.collections)
+            self.blacklist = _validate_collections_param(self.collections)
 
         if options:
             raise ValueError("Unknown options: {}".format(", ".join(options)))
diff --git a/vdirsyncer/cli/discover.py b/vdirsyncer/cli/discover.py
index c28af141..84e7bda1 100644
--- a/vdirsyncer/cli/discover.py
+++ b/vdirsyncer/cli/discover.py
@@ -97,6 +97,7 @@ async def collections_for_pair(
     rv = await aiostream.stream.list(
         expand_collections(
             shortcuts=pair.collections,
+            blacklist=pair.blacklist,
             config_a=pair.config_a,
             config_b=pair.config_b,
             get_a_discovered=a_discovered.get_self,
@@ -194,6 +195,7 @@ async def _discover(self):
 
 async def expand_collections(
     shortcuts,
+    blacklist,
     config_a,
     config_b,
     get_a_discovered,
@@ -221,6 +223,10 @@ async def expand_collections(
 
             if collection in handled_collections:
                 continue
+            elif collection[0] == "!":
+                continue
+            elif collection in blacklist:
+                continue
             handled_collections.add(collection)
 
             a_args = await _collection_from_discovered(