diff --git a/spacy/errors.py b/spacy/errors.py
index 5651ab0fa..9264ca6d1 100644
--- a/spacy/errors.py
+++ b/spacy/errors.py
@@ -356,8 +356,8 @@ class Errors:
     E098 = ("Invalid pattern: expected both RIGHT_ID and RIGHT_ATTRS.")
     E099 = ("Invalid pattern: the first node of pattern should be an anchor "
             "node. The node should only contain RIGHT_ID and RIGHT_ATTRS.")
-    E100 = ("Nodes other than the anchor node should all contain LEFT_ID, "
-            "REL_OP and RIGHT_ID.")
+    E100 = ("Nodes other than the anchor node should all contain {required}, "
+            "but these are missing: {missing}")
     E101 = ("RIGHT_ID should be a new node and LEFT_ID should already have "
             "have been declared in previous edges.")
     E102 = ("Can't merge non-disjoint spans. '{token}' is already part of "
diff --git a/spacy/matcher/dependencymatcher.pyx b/spacy/matcher/dependencymatcher.pyx
index b6e84a5da..9e0842d59 100644
--- a/spacy/matcher/dependencymatcher.pyx
+++ b/spacy/matcher/dependencymatcher.pyx
@@ -122,13 +122,17 @@ cdef class DependencyMatcher:
                     raise ValueError(Errors.E099.format(key=key))
                 visited_nodes[relation["RIGHT_ID"]] = True
             else:
-                if not(
-                    "RIGHT_ID" in relation
-                    and "RIGHT_ATTRS" in relation
-                    and "REL_OP" in relation
-                    and "LEFT_ID" in relation
-                ):
-                    raise ValueError(Errors.E100.format(key=key))
+                required_keys = set(
+                    ("RIGHT_ID", "RIGHT_ATTRS", "REL_OP", "LEFT_ID")
+                )
+                relation_keys = set(relation.keys())
+                missing = required_keys - relation_keys
+                if missing:
+                    missing_txt = ", ".join(list(missing))
+                    raise ValueError(Errors.E100.format(
+                        required=required_keys,
+                        missing=missing_txt
+                    ))
                 if (
                     relation["RIGHT_ID"] in visited_nodes
                     or relation["LEFT_ID"] not in visited_nodes