diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 7eae34f95a..a5b9299d1c 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -21319,7 +21319,7 @@ namespace ts {
                 n.parent.kind !== SyntaxKind.ClassDeclaration &&
                 n.parent.kind !== SyntaxKind.ClassExpression &&
                 n.flags & NodeFlags.Ambient) {
-                if (!(flags & ModifierFlags.Ambient)) {
+                if (!(flags & ModifierFlags.Ambient) && !(isModuleBlock(n.parent) && isModuleDeclaration(n.parent.parent) && isGlobalScopeAugmentation(n.parent.parent))) {
                     // It is nested in an ambient context, which means it is automatically exported
                     flags |= ModifierFlags.Export;
                 }
diff --git a/tests/baselines/reference/globalFunctionAugmentationOverload.js b/tests/baselines/reference/globalFunctionAugmentationOverload.js
new file mode 100644
index 0000000000..50593cca1d
--- /dev/null
+++ b/tests/baselines/reference/globalFunctionAugmentationOverload.js
@@ -0,0 +1,19 @@
+//// [tests/cases/compiler/globalFunctionAugmentationOverload.ts] ////
+
+//// [mod.d.ts]
+declare function expect(spy: Function): void;
+declare module "mod" {
+    class mod {}
+    export = mod;
+}
+//// [mine.ts]
+import "mod";
+
+declare global {
+    function expect(element: string): void;
+}
+
+//// [mine.js]
+"use strict";
+exports.__esModule = true;
+require("mod");
diff --git a/tests/baselines/reference/globalFunctionAugmentationOverload.symbols b/tests/baselines/reference/globalFunctionAugmentationOverload.symbols
new file mode 100644
index 0000000000..dc37397312
--- /dev/null
+++ b/tests/baselines/reference/globalFunctionAugmentationOverload.symbols
@@ -0,0 +1,25 @@
+=== tests/cases/compiler/mod.d.ts ===
+declare function expect(spy: Function): void;
+>expect : Symbol(expect, Decl(mod.d.ts, 0, 0), Decl(mine.ts, 2, 16))
+>spy : Symbol(spy, Decl(mod.d.ts, 0, 24))
+>Function : Symbol(Function, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+
+declare module "mod" {
+>"mod" : Symbol("mod", Decl(mod.d.ts, 0, 45))
+
+    class mod {}
+>mod : Symbol(mod, Decl(mod.d.ts, 1, 22))
+
+    export = mod;
+>mod : Symbol(mod, Decl(mod.d.ts, 1, 22))
+}
+=== tests/cases/compiler/mine.ts ===
+import "mod";
+
+declare global {
+>global : Symbol(global, Decl(mine.ts, 0, 13))
+
+    function expect(element: string): void;
+>expect : Symbol(expect, Decl(mod.d.ts, 0, 0), Decl(mine.ts, 2, 16))
+>element : Symbol(element, Decl(mine.ts, 3, 20))
+}
diff --git a/tests/baselines/reference/globalFunctionAugmentationOverload.types b/tests/baselines/reference/globalFunctionAugmentationOverload.types
new file mode 100644
index 0000000000..03e973af8c
--- /dev/null
+++ b/tests/baselines/reference/globalFunctionAugmentationOverload.types
@@ -0,0 +1,25 @@
+=== tests/cases/compiler/mod.d.ts ===
+declare function expect(spy: Function): void;
+>expect : { (spy: Function): void; (element: string): void; }
+>spy : Function
+>Function : Function
+
+declare module "mod" {
+>"mod" : typeof import("mod")
+
+    class mod {}
+>mod : mod
+
+    export = mod;
+>mod : mod
+}
+=== tests/cases/compiler/mine.ts ===
+import "mod";
+
+declare global {
+>global : typeof global
+
+    function expect(element: string): void;
+>expect : { (spy: Function): void; (element: string): void; }
+>element : string
+}
diff --git a/tests/cases/compiler/globalFunctionAugmentationOverload.ts b/tests/cases/compiler/globalFunctionAugmentationOverload.ts
new file mode 100644
index 0000000000..7f46d26213
--- /dev/null
+++ b/tests/cases/compiler/globalFunctionAugmentationOverload.ts
@@ -0,0 +1,12 @@
+// @filename: mod.d.ts
+declare function expect(spy: Function): void;
+declare module "mod" {
+    class mod {}
+    export = mod;
+}
+// @filename: mine.ts
+import "mod";
+
+declare global {
+    function expect(element: string): void;
+}
\ No newline at end of file