diff --git a/.eslintrc b/.eslintrc
index 85e957da..16f5f9f7 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -20,7 +20,12 @@
     "node": true
   },
   "settings": {
-    "import/extensions": [".js", ".ts"]
+    "import/extensions": [".js", ".ts"],
+    "import/resolver": {
+      "typescript": {
+        "project": ["./tsconfig.json"]
+      }
+    }
   },
   "rules": {
     "@typescript-eslint/no-unused-vars": [
diff --git a/src/index.ts b/src/index.ts
index de84ece0..53baf221 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,6 +1,6 @@
-export * from './error'
-export * from './struct'
-export * from './structs/coercions'
-export * from './structs/refinements'
-export * from './structs/types'
-export * from './structs/utilities'
+export * from './error.js'
+export * from './struct.js'
+export * from './structs/coercions.js'
+export * from './structs/refinements.js'
+export * from './structs/types.js'
+export * from './structs/utilities.js'
diff --git a/src/struct.ts b/src/struct.ts
index b482fd3b..9a5c37ec 100644
--- a/src/struct.ts
+++ b/src/struct.ts
@@ -1,5 +1,5 @@
-import { toFailures, shiftIterator, StructSchema, run } from './utils'
-import { StructError, Failure } from './error'
+import { toFailures, shiftIterator, StructSchema, run } from './utils.js'
+import { StructError, Failure } from './error.js'
 
 /**
  * `Struct` objects encapsulate the validation logic for a specific type of
diff --git a/src/structs/coercions.ts b/src/structs/coercions.ts
index 6dca4ece..62566c50 100644
--- a/src/structs/coercions.ts
+++ b/src/structs/coercions.ts
@@ -1,6 +1,6 @@
-import { Struct, is, Coercer } from '../struct'
-import { isPlainObject } from '../utils'
-import { string, unknown } from './types'
+import { Struct, is, Coercer } from '../struct.js'
+import { isPlainObject } from '../utils.js'
+import { string, unknown } from './types.js'
 
 /**
  * Augment a `Struct` to add an additional coercion step to its input.
diff --git a/src/structs/refinements.ts b/src/structs/refinements.ts
index e3f7736d..276bc925 100644
--- a/src/structs/refinements.ts
+++ b/src/structs/refinements.ts
@@ -1,5 +1,5 @@
-import { Struct, Refiner } from '../struct'
-import { toFailures } from '../utils'
+import { Struct, Refiner } from '../struct.js'
+import { toFailures } from '../utils.js'
 
 /**
  * Ensure that a string, array, map, or set is empty.
diff --git a/src/structs/types.ts b/src/structs/types.ts
index 8bcc0ef3..19493104 100644
--- a/src/structs/types.ts
+++ b/src/structs/types.ts
@@ -1,5 +1,5 @@
-import { Infer, Struct } from '../struct'
-import { define } from './utilities'
+import { Infer, Struct } from '../struct.js'
+import { define } from './utilities.js'
 import {
   ObjectSchema,
   ObjectType,
@@ -9,7 +9,7 @@ import {
   AnyStruct,
   InferStructTuple,
   UnionToIntersection,
-} from '../utils'
+} from '../utils.js'
 
 /**
  * Ensure that any value passes validation.
diff --git a/src/structs/utilities.ts b/src/structs/utilities.ts
index d2162a3d..18b60e76 100644
--- a/src/structs/utilities.ts
+++ b/src/structs/utilities.ts
@@ -1,6 +1,6 @@
-import { Context, Struct, Validator } from '../struct'
-import { Assign, ObjectSchema, ObjectType, PartialObjectSchema } from '../utils'
-import { object, optional, type } from './types'
+import { Context, Struct, Validator } from '../struct.js'
+import { Assign, ObjectSchema, ObjectType, PartialObjectSchema } from '../utils.js'
+import { object, optional, type } from './types.js'
 
 /**
  * Create a new struct that combines the properties properties from multiple
diff --git a/src/utils.ts b/src/utils.ts
index 92df9755..0928871a 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,5 +1,5 @@
-import { Struct, Infer, Result, Context, Describe } from './struct'
-import { Failure } from './error'
+import { Struct, Infer, Result, Context, Describe } from './struct.js'
+import { Failure } from './error.js'
 
 /**
  * Check if a value is an iterator.