diff --git a/application/src/main/java/net/corda/v5/application/persistence/ParameterizedQuery.java b/application/src/main/java/net/corda/v5/application/persistence/ParameterizedQuery.java
index 4eff6c474c..4b511b16e0 100644
--- a/application/src/main/java/net/corda/v5/application/persistence/ParameterizedQuery.java
+++ b/application/src/main/java/net/corda/v5/application/persistence/ParameterizedQuery.java
@@ -1,6 +1,7 @@
 package net.corda.v5.application.persistence;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.Map;
 
@@ -54,7 +55,7 @@ public interface ParameterizedQuery<R> extends PagedQuery<R> {
      * @return the same {@link ParameterizedQuery} instance.
      */
     @NotNull
-    ParameterizedQuery<R> setParameter(@NotNull String name, @NotNull Object value);
+    ParameterizedQuery<R> setParameter(@NotNull String name, @Nullable Object value);
 
     /**
      * Sets the parameters as a {@link Map}.
diff --git a/data/avro-schema/src/main/resources/avro/net/corda/data/persistence/FindWithNamedQuery.avsc b/data/avro-schema/src/main/resources/avro/net/corda/data/persistence/FindWithNamedQuery.avsc
index 339a9c73c0..a7c3d440af 100644
--- a/data/avro-schema/src/main/resources/avro/net/corda/data/persistence/FindWithNamedQuery.avsc
+++ b/data/avro-schema/src/main/resources/avro/net/corda/data/persistence/FindWithNamedQuery.avsc
@@ -13,7 +13,7 @@
       "name": "parameters",
       "type": {
         "type": "map",
-        "values": "bytes"
+        "values": ["null", "bytes"]
       },
       "doc": "Parameters for the query, with each value represented as a bytes array payload serialized in AMQP format. Null values must be tested using IS NULL in the query; it is not possible to pass in a null as a parameter value. "
     },
diff --git a/gradle.properties b/gradle.properties
index d961b91108..ff3f0c1f1f 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -5,7 +5,7 @@ cordaProductVersion = 5.2.0
 # NOTE: update this each time this module contains a breaking change
 ## NOTE: currently this is a top level revision, so all API versions will line up, but this could be moved to
 ##   a per module property in which case module versions can change independently.
-cordaApiRevision = 21
+cordaApiRevision = 22
 
 # Main
 kotlin.stdlib.default.dependency = false
diff --git a/ledger/ledger-utxo/src/main/java/net/corda/v5/ledger/utxo/query/VaultNamedParameterizedQuery.java b/ledger/ledger-utxo/src/main/java/net/corda/v5/ledger/utxo/query/VaultNamedParameterizedQuery.java
index eb44784857..cd1bc0ebe3 100644
--- a/ledger/ledger-utxo/src/main/java/net/corda/v5/ledger/utxo/query/VaultNamedParameterizedQuery.java
+++ b/ledger/ledger-utxo/src/main/java/net/corda/v5/ledger/utxo/query/VaultNamedParameterizedQuery.java
@@ -7,6 +7,7 @@
 import net.corda.v5.ledger.utxo.StateAndRef;
 import net.corda.v5.ledger.utxo.UtxoLedgerService;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.time.Instant;
 import java.util.Map;
@@ -45,7 +46,7 @@ public interface VaultNamedParameterizedQuery<R> extends ParameterizedQuery<R> {
      */
     @Override
     @NotNull
-    VaultNamedParameterizedQuery<R> setParameter(@NotNull String name, @NotNull Object value);
+    VaultNamedParameterizedQuery<R> setParameter(@NotNull String name, @Nullable Object value);
 
     /**
      * @see ParameterizedQuery#setParameters(Map)