diff --git a/.flowconfig b/.flowconfig
index 52ade89a1f..d963c3d3f6 100644
--- a/.flowconfig
+++ b/.flowconfig
@@ -13,4 +13,4 @@ suppress_comment=\\(.\\|\n\\)*\\$FlowFixMe\\($\\|[^(]\\|(\\(<VERSION>\\)?)\\)
 suppress_comment=\\(.\\|\n\\)*\\$FlowIssue\\((\\(<VERSION>\\)?)\\)?:? #[0-9]+
 
 [version]
-^0.84.0
+^0.86.0
diff --git a/package.json b/package.json
index 49fff69ad5..72a5e0f745 100644
--- a/package.json
+++ b/package.json
@@ -69,7 +69,7 @@
     "eslint": "5.8.0",
     "eslint-plugin-flowtype": "3.1.4",
     "eslint-plugin-prettier": "3.0.0",
-    "flow-bin": "0.84.0",
+    "flow-bin": "0.86.0",
     "mocha": "5.2.0",
     "nyc": "13.1.0",
     "prettier": "1.14.3",
diff --git a/src/utilities/buildASTSchema.js b/src/utilities/buildASTSchema.js
index 2319e740b3..f2a1170125 100644
--- a/src/utilities/buildASTSchema.js
+++ b/src/utilities/buildASTSchema.js
@@ -286,7 +286,7 @@ export class ASTDefinitionBuilder {
     });
   }
 
-  buildField(field: FieldDefinitionNode): GraphQLFieldConfig<*, *> {
+  buildField(field: FieldDefinitionNode): GraphQLFieldConfig<mixed, mixed> {
     return {
       // Note: While this could make assertions to get the correctly typed
       // value, that would throw immediately while type system validation
@@ -360,7 +360,7 @@ export class ASTDefinitionBuilder {
     def: ObjectTypeDefinitionNode | InterfaceTypeDefinitionNode,
   ) {
     return def.fields
-      ? keyValMap(
+      ? keyValMap<_, GraphQLFieldConfig<mixed, mixed>>(
           def.fields,
           field => field.name.value,
           field => this.buildField(field),
@@ -369,7 +369,7 @@ export class ASTDefinitionBuilder {
   }
 
   _makeInputValues(values: $ReadOnlyArray<InputValueDefinitionNode>) {
-    return keyValMap(
+    return keyValMap<_, GraphQLInputField>(
       values,
       value => value.name.value,
       value => this.buildInputField(value),
@@ -396,7 +396,7 @@ export class ASTDefinitionBuilder {
 
   _makeValueDefMap(def: EnumTypeDefinitionNode) {
     return def.values
-      ? keyValMap(
+      ? keyValMap<_, GraphQLEnumValueConfig>(
           def.values,
           enumValue => enumValue.name.value,
           enumValue => this.buildEnumValue(enumValue),
diff --git a/yarn.lock b/yarn.lock
index ee90da8613..70196695a2 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1731,10 +1731,10 @@ flat-cache@^1.2.1:
     graceful-fs "^4.1.2"
     write "^0.2.1"
 
-flow-bin@0.84.0:
-  version "0.84.0"
-  resolved "https://registry.yarnpkg.com/flow-bin/-/flow-bin-0.84.0.tgz#4cb2364c750fb37a7840524fa62456b53f64cdcb"
-  integrity sha512-ocji8eEYp+YfICsm+F6cIHUcD7v5sb0/ADEXm6gyUKdjQzmSckMrPUdZtyfP973t3YGHKliUMxMvIBHyR5LbXQ==
+flow-bin@0.86.0:
+  version "0.86.0"
+  resolved "https://registry.yarnpkg.com/flow-bin/-/flow-bin-0.86.0.tgz#153a28722b4dc13b7200c74b644dd4d9f4969a11"
+  integrity sha512-ulRvFH3ewGIYwg+qPk/OJXoe3Nhqi0RyR0wqgK0b1NzUDEC6O99zU39MBTickXvlrr6iwRO6Wm4lVGeDmnzbew==
 
 for-in@^1.0.2:
   version "1.0.2"