diff --git a/packages/delegate/package.json b/packages/delegate/package.json
index 805a9afda83..cbec4ac71fc 100644
--- a/packages/delegate/package.json
+++ b/packages/delegate/package.json
@@ -21,10 +21,11 @@
     "@graphql-tools/schema": "6.0.16",
     "@graphql-tools/utils": "6.0.16",
     "@ardatan/aggregate-error": "0.0.1",
+    "is-promise": "4.0.0",
     "tslib": "~2.0.0"
   },
   "publishConfig": {
     "access": "public",
     "directory": "dist"
   }
-}
\ No newline at end of file
+}
diff --git a/packages/delegate/src/delegateToSchema.ts b/packages/delegate/src/delegateToSchema.ts
index 5051e7b3abf..0fd0908e807 100644
--- a/packages/delegate/src/delegateToSchema.ts
+++ b/packages/delegate/src/delegateToSchema.ts
@@ -13,6 +13,8 @@ import {
   GraphQLObjectType,
 } from 'graphql';
 
+import isPromise from 'is-promise';
+
 import { mapAsyncIterator, Transform, ExecutionResult } from '@graphql-tools/utils';
 
 import { IDelegateToSchemaOptions, IDelegateRequestOptions, SubschemaConfig, ExecutionParams } from './types';
@@ -162,7 +164,7 @@ export function delegateRequest({
       info,
     });
 
-    if (executionResult instanceof Promise) {
+    if (isPromise(executionResult)) {
       return executionResult.then(originalResult => transformer.transformResult(originalResult));
     }
     return transformer.transformResult(executionResult);
diff --git a/packages/delegate/src/results/mergeFields.ts b/packages/delegate/src/results/mergeFields.ts
index d36e8d5eb50..a84773dd47c 100644
--- a/packages/delegate/src/results/mergeFields.ts
+++ b/packages/delegate/src/results/mergeFields.ts
@@ -1,4 +1,5 @@
 import { FieldNode, SelectionNode, Kind, GraphQLResolveInfo, SelectionSetNode } from 'graphql';
+import isPromise from 'is-promise';
 
 import { MergedTypeInfo, SubschemaConfig } from '../types';
 
@@ -153,7 +154,7 @@ export function mergeFields(
   delegationMap.forEach((selectionSet: SelectionSetNode, s: SubschemaConfig) => {
     const maybePromise = s.merge[typeName].resolve(object, context, info, s, selectionSet);
     maybePromises.push(maybePromise);
-    if (!containsPromises && maybePromise instanceof Promise) {
+    if (!containsPromises && isPromise(maybePromise)) {
       containsPromises = true;
     }
   });
diff --git a/packages/links/package.json b/packages/links/package.json
index 65f5f2d8fb5..b6630ce0884 100644
--- a/packages/links/package.json
+++ b/packages/links/package.json
@@ -26,12 +26,13 @@
     "@graphql-tools/utils": "6.0.16",
     "apollo-link": "1.2.14",
     "apollo-upload-client": "14.1.1",
-    "form-data": "3.0.0",
     "cross-fetch": "3.0.5",
+    "form-data": "3.0.0",
+    "is-promise": "4.0.0",
     "tslib": "~2.0.0"
   },
   "publishConfig": {
     "access": "public",
     "directory": "dist"
   }
-}
\ No newline at end of file
+}
diff --git a/packages/links/src/GraphQLUpload.ts b/packages/links/src/GraphQLUpload.ts
index 62493f4bac4..a33701c9cb8 100644
--- a/packages/links/src/GraphQLUpload.ts
+++ b/packages/links/src/GraphQLUpload.ts
@@ -1,13 +1,14 @@
 import { GraphQLScalarType, GraphQLError } from 'graphql';
+import isPromise from 'is-promise';
 
 const GraphQLUpload = new GraphQLScalarType({
   name: 'Upload',
   description: 'The `Upload` scalar type represents a file upload.',
   parseValue: value => {
-    if (value != null && value.promise instanceof Promise) {
+    if (value != null && isPromise(value.promise)) {
       // graphql-upload v10
       return value.promise;
-    } else if (value instanceof Promise) {
+    } else if (isPromise(value)) {
       // graphql-upload v9
       return value;
     }
diff --git a/packages/stitch/package.json b/packages/stitch/package.json
index 7dea9755e8d..331ba253a90 100644
--- a/packages/stitch/package.json
+++ b/packages/stitch/package.json
@@ -27,10 +27,11 @@
     "@graphql-tools/schema": "6.0.16",
     "@graphql-tools/utils": "6.0.16",
     "@graphql-tools/wrap": "6.0.16",
+    "is-promise": "4.0.0",
     "tslib": "~2.0.0"
   },
   "publishConfig": {
     "access": "public",
     "directory": "dist"
   }
-}
\ No newline at end of file
+}
diff --git a/packages/stitch/tests/fixtures/schemas.ts b/packages/stitch/tests/fixtures/schemas.ts
index 09a5365d3e0..cf0798c64c9 100644
--- a/packages/stitch/tests/fixtures/schemas.ts
+++ b/packages/stitch/tests/fixtures/schemas.ts
@@ -11,6 +11,7 @@ import {
   GraphQLError,
   GraphQLInterfaceType,
 } from 'graphql';
+import isPromise from 'is-promise';
 
 import { introspectSchema } from '@graphql-tools/wrap';
 import {
@@ -689,7 +690,7 @@ function makeExecutorFromSchema(schema: GraphQLSchema) {
       context,
       variables,
     ) as PromiseOrValue<ExecutionResult<TReturn>>;
-    if (result instanceof Promise) {
+    if (isPromise(result)) {
       return result.then(originalResult => JSON.parse(JSON.stringify(originalResult)));
     }
     return JSON.parse(JSON.stringify(result));
@@ -705,7 +706,7 @@ function makeSubscriberFromSchema(schema: GraphQLSchema) {
       context,
       variables,
     ) as Promise<AsyncIterator<ExecutionResult<TReturn>> | ExecutionResult<TReturn>>;
-    if (result instanceof Promise) {
+    if (isPromise(result)) {
       return result.then(asyncIterator =>
         mapAsyncIterator(asyncIterator as AsyncIterator<ExecutionResult>, (originalResult: ExecutionResult<TReturn>) => JSON.parse(JSON.stringify(originalResult))));
     }
diff --git a/packages/wrap/package.json b/packages/wrap/package.json
index 53130d28bf8..e8d0a45b3e0 100644
--- a/packages/wrap/package.json
+++ b/packages/wrap/package.json
@@ -22,10 +22,11 @@
     "@graphql-tools/schema": "6.0.16",
     "@graphql-tools/utils": "6.0.16",
     "aggregate-error": "3.0.1",
+    "is-promise": "4.0.0",
     "tslib": "~2.0.0"
   },
   "publishConfig": {
     "access": "public",
     "directory": "dist"
   }
-}
\ No newline at end of file
+}
diff --git a/packages/wrap/tests/fixtures/schemas.ts b/packages/wrap/tests/fixtures/schemas.ts
index bf2fe7df7e0..a13a9099499 100644
--- a/packages/wrap/tests/fixtures/schemas.ts
+++ b/packages/wrap/tests/fixtures/schemas.ts
@@ -11,6 +11,7 @@ import {
   GraphQLError,
   GraphQLInterfaceType,
 } from 'graphql';
+import isPromise from 'is-promise';
 
 import { introspectSchema } from '../../src/introspect';
 import {
@@ -689,7 +690,7 @@ function makeExecutorFromSchema(schema: GraphQLSchema) {
       context,
       variables,
     ) as PromiseOrValue<ExecutionResult<TReturn>>;
-    if (result instanceof Promise) {
+    if (isPromise(result)) {
       return result.then(originalResult => JSON.parse(JSON.stringify(originalResult)));
     }
     return JSON.parse(JSON.stringify(result));
@@ -705,7 +706,7 @@ function makeSubscriberFromSchema(schema: GraphQLSchema) {
       context,
       variables,
     ) as Promise<AsyncIterator<ExecutionResult<TReturn>> | ExecutionResult<TReturn>>;
-    if (result instanceof Promise) {
+    if (isPromise(result)) {
       return result.then(asyncIterator =>
         mapAsyncIterator(asyncIterator as AsyncIterator<ExecutionResult>, (originalResult: ExecutionResult<TReturn>) => JSON.parse(JSON.stringify(originalResult))));
     }
diff --git a/yarn.lock b/yarn.lock
index 92164b5b0a2..8002ea72e11 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -7770,6 +7770,11 @@ is-potential-custom-element-name@^1.0.0:
   resolved "https://registry.yarnpkg.com/is-potential-custom-element-name/-/is-potential-custom-element-name-1.0.0.tgz#0c52e54bcca391bb2c494b21e8626d7336c6e397"
   integrity sha1-DFLlS8yjkbssSUsh6GJtczbG45c=
 
+is-promise@4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/is-promise/-/is-promise-4.0.0.tgz#42ff9f84206c1991d26debf520dd5c01042dd2f3"
+  integrity sha512-hvpoI6korhJMnej285dSg6nu1+e6uxs7zG3BYAm5byqDsgJNWwxzM6z6iZiAgQR4TJ30JmBTOwqZUw3WlyH3AQ==
+
 is-regex@^1.0.4, is-regex@^1.0.5:
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/is-regex/-/is-regex-1.0.5.tgz#39d589a358bf18967f726967120b8fc1aed74eae"