diff --git a/examples/kitchen-sink/schema.sql b/examples/kitchen-sink/schema.sql
index 5924cddace..d37253bb34 100644
--- a/examples/kitchen-sink/schema.sql
+++ b/examples/kitchen-sink/schema.sql
@@ -78,6 +78,10 @@ create table a.foreign_key (
   foreign key (compound_key_1, compound_key_2) references c.compound_key(person_id_1, person_id_2)
 );
 
+create table c.edge_case (
+  not_null_has_default boolean not null default false
+);
+
 create domain a.an_int as integer;
 create domain b.another_int as a.an_int;
 
diff --git a/src/graphql/schema/collection/mutations/createCreateCollectionMutationFieldEntry.ts b/src/graphql/schema/collection/mutations/createCreateCollectionMutationFieldEntry.ts
index 003a08ceb3..ac672f9c3b 100644
--- a/src/graphql/schema/collection/mutations/createCreateCollectionMutationFieldEntry.ts
+++ b/src/graphql/schema/collection/mutations/createCreateCollectionMutationFieldEntry.ts
@@ -74,8 +74,10 @@ export default function createCreateCollectionMutationFieldEntry (
     execute: (context, input) => {
       const value = transformGQLInputValue(inputFieldType, input[inputFieldName])
 
-      if (!collection.type.isTypeOf(value))
-        throw new Error(`Created object is not of the correct type for collection '${collection.name}'.`)
+      // TODO: This can’t be the best solution? `isTypeOf` fails though for
+      // default fields that don’t exist.
+      if (!(value instanceof Map))
+        throw new Error('Value must be a `Map`.')
 
       return collection.create!(context, value)
     },
diff --git a/src/postgraphql/__tests__/__snapshots__/postgraphqlIntegrationOperations-test.js.snap b/src/postgraphql/__tests__/__snapshots__/postgraphqlIntegrationOperations-test.js.snap
index 5748015dfe..f0df9952e4 100644
--- a/src/postgraphql/__tests__/__snapshots__/postgraphqlIntegrationOperations-test.js.snap
+++ b/src/postgraphql/__tests__/__snapshots__/postgraphqlIntegrationOperations-test.js.snap
@@ -772,6 +772,16 @@ Object {
         "name": "Best Pal",
       },
     },
+    "e": Object {
+      "edgeCase": Object {
+        "notNullHasDefault": true,
+      },
+    },
+    "f": Object {
+      "edgeCase": Object {
+        "notNullHasDefault": false,
+      },
+    },
   },
 }
 `;
diff --git a/src/postgraphql/__tests__/__snapshots__/postgraphqlIntegrationSchema-test.js.snap b/src/postgraphql/__tests__/__snapshots__/postgraphqlIntegrationSchema-test.js.snap
index 8c998e502d..eec1ab1f6b 100644
--- a/src/postgraphql/__tests__/__snapshots__/postgraphqlIntegrationSchema-test.js.snap
+++ b/src/postgraphql/__tests__/__snapshots__/postgraphqlIntegrationSchema-test.js.snap
@@ -83,6 +83,21 @@ type CreateCompoundKeyPayload {
   query: Query
 }
 
+input CreateEdgeCaseInput {
+  clientMutationId: String
+  edgeCase: EdgeCaseInput!
+}
+
+type CreateEdgeCasePayload {
+  clientMutationId: String
+  edgeCase: EdgeCase
+  edgeCaseEdge(
+    # The method to use when ordering \`EdgeCase\`.
+    orderBy: EdgeCasesOrderBy = NATURAL
+  ): EdgeCasesEdge
+  query: Query
+}
+
 input CreatePersonInput {
   clientMutationId: String
   person: PersonInput!
@@ -151,6 +166,45 @@ type DeletePersonPayload {
   query: Query
 }
 
+type EdgeCase {
+  notNullHasDefault: Boolean!
+}
+
+input EdgeCaseInput {
+  notNullHasDefault: Boolean
+}
+
+# A connection to a list of \`EdgeCase\` values.
+type EdgeCasesConnection {
+  # Information to aid in pagination.
+  pageInfo: PageInfo!
+
+  # The count of *all* \`EdgeCase\` you could get from the connection.
+  totalCount: Int
+
+  # A list of edges which contains the \`EdgeCase\` and cursor to aid in pagination.
+  edges: [EdgeCasesEdge]
+
+  # A list of \`EdgeCase\` objects.
+  nodes: [EdgeCase!]
+}
+
+# A \`EdgeCase\` edge in the connection.
+type EdgeCasesEdge {
+  # A cursor for use in pagination.
+  cursor: Cursor
+
+  # The \`EdgeCase\` at the end of the edge.
+  node: EdgeCase!
+}
+
+# Methods to use when ordering \`EdgeCase\`.
+enum EdgeCasesOrderBy {
+  NATURAL
+  NOT_NULL_HAS_DEFAULT_ASC
+  NOT_NULL_HAS_DEFAULT_DESC
+}
+
 scalar Email
 
 input FloatRangeBoundInput {
@@ -221,6 +275,7 @@ type Mutation {
   updateCompoundKeyByPersonId1AndPersonId2(input: UpdateCompoundKeyByPersonId1AndPersonId2Input!): UpdateCompoundKeyPayload
   deleteCompoundKey(input: DeleteCompoundKeyInput!): DeleteCompoundKeyPayload
   deleteCompoundKeyByPersonId1AndPersonId2(input: DeleteCompoundKeyByPersonId1AndPersonId2Input!): DeleteCompoundKeyPayload
+  createEdgeCase(input: CreateEdgeCaseInput!): CreateEdgeCasePayload
   createPerson(input: CreatePersonInput!): CreatePersonPayload
   updatePerson(input: UpdatePersonInput!): UpdatePersonPayload
   updatePersonByEmail(input: UpdatePersonByEmailInput!): UpdatePersonPayload
@@ -528,6 +583,29 @@ type Query implements Node {
   ): CompoundKey
   compoundKeyByPersonId1AndPersonId2(personId1: Int!, personId2: Int!): CompoundKey
 
+  # Reads and enables paginatation through a set of \`EdgeCase\`.
+  allEdgeCases(
+    # The method to use when ordering \`EdgeCase\`.
+    orderBy: EdgeCasesOrderBy = NATURAL
+
+    # Read all values in the set before (above) this cursor.
+    before: Cursor
+
+    # Read all values in the set after (below) this cursor.
+    after: Cursor
+
+    # Only read the first \`n\` values of the set.
+    first: Int
+
+    # Only read the last \`n\` values of the set.
+    last: Int
+
+    # Skip the first \`n\` values from our \`after\` cursor, an alternative to cursor
+    # based pagination. May not be used with \`last\`.
+    offset: Int
+    notNullHasDefault: Boolean
+  ): EdgeCasesConnection
+
   # Reads and enables paginatation through a set of \`Person\`.
   allPeople(
     # The method to use when ordering \`Person\`.
@@ -1549,6 +1627,21 @@ type CreateCompoundKeyPayload {
   query: Query
 }
 
+input CreateEdgeCaseInput {
+  clientMutationId: String
+  edgeCase: EdgeCaseInput!
+}
+
+type CreateEdgeCasePayload {
+  clientMutationId: String
+  edgeCase: EdgeCase
+  edgeCaseEdge(
+    # The method to use when ordering \`EdgeCase\`.
+    orderBy: EdgeCasesOrderBy = NATURAL
+  ): EdgeCasesEdge
+  query: Query
+}
+
 input CreateForeignKeyInput {
   clientMutationId: String
   foreignKey: ForeignKeyInput!
@@ -1748,6 +1841,45 @@ type DeleteTypePayload {
   query: Query
 }
 
+type EdgeCase {
+  notNullHasDefault: Boolean!
+}
+
+input EdgeCaseInput {
+  notNullHasDefault: Boolean
+}
+
+# A connection to a list of \`EdgeCase\` values.
+type EdgeCasesConnection {
+  # Information to aid in pagination.
+  pageInfo: PageInfo!
+
+  # The count of *all* \`EdgeCase\` you could get from the connection.
+  totalCount: Int
+
+  # A list of edges which contains the \`EdgeCase\` and cursor to aid in pagination.
+  edges: [EdgeCasesEdge]
+
+  # A list of \`EdgeCase\` objects.
+  nodes: [EdgeCase!]
+}
+
+# A \`EdgeCase\` edge in the connection.
+type EdgeCasesEdge {
+  # A cursor for use in pagination.
+  cursor: Cursor
+
+  # The \`EdgeCase\` at the end of the edge.
+  node: EdgeCase!
+}
+
+# Methods to use when ordering \`EdgeCase\`.
+enum EdgeCasesOrderBy {
+  NATURAL
+  NOT_NULL_HAS_DEFAULT_ASC
+  NOT_NULL_HAS_DEFAULT_DESC
+}
+
 scalar Email
 
 # range of numerics
@@ -1987,6 +2119,7 @@ type Mutation {
   updateCompoundKeyByPersonId1AndPersonId2(input: UpdateCompoundKeyByPersonId1AndPersonId2Input!): UpdateCompoundKeyPayload
   deleteCompoundKey(input: DeleteCompoundKeyInput!): DeleteCompoundKeyPayload
   deleteCompoundKeyByPersonId1AndPersonId2(input: DeleteCompoundKeyByPersonId1AndPersonId2Input!): DeleteCompoundKeyPayload
+  createEdgeCase(input: CreateEdgeCaseInput!): CreateEdgeCasePayload
   createPerson(input: CreatePersonInput!): CreatePersonPayload
   updatePerson(input: UpdatePersonInput!): UpdatePersonPayload
   updatePersonByEmail(input: UpdatePersonByEmailInput!): UpdatePersonPayload
@@ -2616,6 +2749,29 @@ type Query implements Node {
   ): CompoundKey
   compoundKeyByPersonId1AndPersonId2(personId1: Int!, personId2: Int!): CompoundKey
 
+  # Reads and enables paginatation through a set of \`EdgeCase\`.
+  allEdgeCases(
+    # The method to use when ordering \`EdgeCase\`.
+    orderBy: EdgeCasesOrderBy = NATURAL
+
+    # Read all values in the set before (above) this cursor.
+    before: Cursor
+
+    # Read all values in the set after (below) this cursor.
+    after: Cursor
+
+    # Only read the first \`n\` values of the set.
+    first: Int
+
+    # Only read the last \`n\` values of the set.
+    last: Int
+
+    # Skip the first \`n\` values from our \`after\` cursor, an alternative to cursor
+    # based pagination. May not be used with \`last\`.
+    offset: Int
+    notNullHasDefault: Boolean
+  ): EdgeCasesConnection
+
   # Reads and enables paginatation through a set of \`Person\`.
   allPeople(
     # The method to use when ordering \`Person\`.
diff --git a/src/postgraphql/__tests__/fixtures/queries/mutation-create.graphql b/src/postgraphql/__tests__/fixtures/queries/mutation-create.graphql
index 93eb415f76..f3a2a645f1 100644
--- a/src/postgraphql/__tests__/fixtures/queries/mutation-create.graphql
+++ b/src/postgraphql/__tests__/fixtures/queries/mutation-create.graphql
@@ -152,6 +152,22 @@ mutation {
       name
     }
   }
+  e: createEdgeCase(input: {
+    edgeCase: {
+      notNullHasDefault: true
+    }
+  }) {
+    edgeCase {
+      notNullHasDefault
+    }
+  }
+  f: createEdgeCase(input: {
+    edgeCase: {}
+  }) {
+    edgeCase {
+      notNullHasDefault
+    }
+  }
 }
 
 fragment createPersonPayload on CreatePersonPayload {
diff --git a/src/postgres/introspection/__tests__/__snapshots__/introspectDatabase-test.js.snap b/src/postgres/introspection/__tests__/__snapshots__/introspectDatabase-test.js.snap
index 6c01fb3801..032e9af7bd 100644
--- a/src/postgres/introspection/__tests__/__snapshots__/introspectDatabase-test.js.snap
+++ b/src/postgres/introspection/__tests__/__snapshots__/introspectDatabase-test.js.snap
@@ -81,6 +81,16 @@ Object {
       "num": 5,
       "typeId": "int4",
     },
+    Object {
+      "classId": "edge_case",
+      "description": null,
+      "hasDefault": true,
+      "isNotNull": true,
+      "kind": "attribute",
+      "name": "not_null_has_default",
+      "num": 1,
+      "typeId": "bool",
+    },
     Object {
       "classId": "foreign_key",
       "description": null,
@@ -587,6 +597,18 @@ Object {
       "namespaceId": "c",
       "typeId": "compound_type",
     },
+    Object {
+      "description": null,
+      "id": "edge_case",
+      "isDeletable": true,
+      "isInsertable": true,
+      "isSelectable": true,
+      "isUpdatable": true,
+      "kind": "class",
+      "name": "edge_case",
+      "namespaceId": "c",
+      "typeId": "edge_case",
+    },
     Object {
       "description": null,
       "id": "foreign_key",
@@ -1468,6 +1490,22 @@ Object {
       "rangeSubTypeId": null,
       "type": "c",
     },
+    Object {
+      "arrayItemTypeId": null,
+      "category": "C",
+      "classId": "edge_case",
+      "description": null,
+      "domainBaseTypeId": null,
+      "domainIsNotNull": false,
+      "enumVariants": null,
+      "id": "edge_case",
+      "kind": "type",
+      "name": "edge_case",
+      "namespaceId": "c",
+      "namespaceName": "c",
+      "rangeSubTypeId": null,
+      "type": "c",
+    },
     Object {
       "arrayItemTypeId": null,
       "category": "S",