diff --git a/src/main/java/graphql/execution/ValuesResolver.java b/src/main/java/graphql/execution/ValuesResolver.java
index cc59de6f8..27487ca55 100644
--- a/src/main/java/graphql/execution/ValuesResolver.java
+++ b/src/main/java/graphql/execution/ValuesResolver.java
@@ -27,6 +27,7 @@
 import graphql.schema.GraphQLScalarType;
 import graphql.schema.GraphQLSchema;
 import graphql.schema.GraphQLType;
+import graphql.schema.GraphQLTypeUtil;
 import graphql.schema.InputValueWithState;
 import graphql.schema.visibility.GraphqlFieldVisibility;
 import org.jetbrains.annotations.NotNull;
@@ -376,8 +377,9 @@ private static Map<String, Object> getArgumentValuesImpl(
                     coercedValues.put(argumentName, value);
                 }
                 // @oneOf input must be checked now that all variables and literals have been converted
-                if (argumentType instanceof GraphQLInputObjectType) {
-                    GraphQLInputObjectType inputObjectType = (GraphQLInputObjectType) argumentType;
+                GraphQLType unwrappedType = GraphQLTypeUtil.unwrapNonNull(argumentType);
+                if (unwrappedType instanceof GraphQLInputObjectType) {
+                    GraphQLInputObjectType inputObjectType = (GraphQLInputObjectType) unwrappedType;
                     if (inputObjectType.isOneOf() && ! ValuesResolverConversion.isNullValue(value)) {
                         validateOneOfInputTypes(inputObjectType, argumentValue, argumentName, value, locale);
                     }
diff --git a/src/test/groovy/graphql/execution/ValuesResolverTest.groovy b/src/test/groovy/graphql/execution/ValuesResolverTest.groovy
index dea17a2c4..0e53791a3 100644
--- a/src/test/groovy/graphql/execution/ValuesResolverTest.groovy
+++ b/src/test/groovy/graphql/execution/ValuesResolverTest.groovy
@@ -23,6 +23,7 @@ import graphql.language.Value
 import graphql.language.VariableDefinition
 import graphql.language.VariableReference
 import graphql.schema.CoercingParseValueException
+import graphql.schema.GraphQLNonNull
 import spock.lang.Specification
 import spock.lang.Unroll
 
@@ -360,16 +361,26 @@ class ValuesResolverTest extends Specification {
                         .type(GraphQLInt)
                         .build())
                 .build()
-        def fieldArgument = newArgument().name("arg").type(inputObjectType).build()
 
-        when:
         def argument = new Argument("arg", inputValue)
+
+        when:
+        def fieldArgument = newArgument().name("arg").type(inputObjectType).build()
         ValuesResolver.getArgumentValues([fieldArgument], [argument], variables, graphQLContext, locale)
 
         then:
         def e = thrown(OneOfTooManyKeysException)
         e.message == "Exactly one key must be specified for OneOf type 'oneOfInputObject'."
 
+        when: "input type is wrapped in non-null"
+        def nonNullInputObjectType = GraphQLNonNull.nonNull(inputObjectType)
+        def fieldArgumentNonNull = newArgument().name("arg").type(nonNullInputObjectType).build()
+        ValuesResolver.getArgumentValues([fieldArgumentNonNull], [argument], variables, graphQLContext, locale)
+
+        then:
+        def eNonNull = thrown(OneOfTooManyKeysException)
+        eNonNull.message == "Exactly one key must be specified for OneOf type 'oneOfInputObject'."
+
         where:
         // from https://github.com/graphql/graphql-spec/pull/825/files#diff-30a69c5a5eded8e1aea52e53dad1181e6ec8f549ca2c50570b035153e2de1c43R1692
         testCase                             | inputValue   | variables
@@ -502,6 +513,44 @@ class ValuesResolverTest extends Specification {
 
     }
 
+    def "getArgumentValues: invalid oneOf input no values where passed - #testCase"() {
+        given: "schema defining input object"
+        def inputObjectType = newInputObject()
+                .name("oneOfInputObject")
+                .withAppliedDirective(Directives.OneOfDirective.toAppliedDirective())
+                .field(newInputObjectField()
+                        .name("a")
+                        .type(GraphQLString)
+                        .build())
+                .field(newInputObjectField()
+                        .name("b")
+                        .type(GraphQLInt)
+                        .build())
+                .build()
+        def fieldArgument = newArgument().name("arg").type(inputObjectType).build()
+
+        when:
+        def argument = new Argument("arg", inputValue)
+        ValuesResolver.getArgumentValues([fieldArgument], [argument], variables, graphQLContext, locale)
+
+        then:
+        def e = thrown(OneOfNullValueException)
+        e.message == "OneOf type field 'oneOfInputObject.a' must be non-null."
+
+        where:
+        // from https://github.com/graphql/graphql-spec/pull/825/files#diff-30a69c5a5eded8e1aea52e53dad1181e6ec8f549ca2c50570b035153e2de1c43R1692
+        testCase                       | inputValue   | variables
+
+        '`{ a: null }` {}'             | buildObjectLiteral([
+                a: NullValue.of()
+        ])                                            | CoercedVariables.emptyVariables()
+
+        '`{ a: $var }`  { var : null}' | buildObjectLiteral([
+                a: VariableReference.of("var")
+        ])                                            | CoercedVariables.of(["var": null])
+
+    }
+
     def "getVariableValues: enum as variable input"() {
         given:
         def enumDef = newEnum()
@@ -839,4 +888,4 @@ class ValuesResolverTest extends Specification {
         executionResult.errors[0].message == "Variable 'input' has an invalid value: Expected a value that can be converted to type 'Float' but it was a 'String'"
         executionResult.errors[0].locations == [new SourceLocation(2, 35)]
     }
-}
\ No newline at end of file
+}