diff --git a/packages/babel-parser/src/util/scope.js b/packages/babel-parser/src/util/scope.js
index a9cf9d89ed..759da8f1ce 100644
--- a/packages/babel-parser/src/util/scope.js
+++ b/packages/babel-parser/src/util/scope.js
@@ -139,10 +139,13 @@ export default class ScopeHandler {
   }
 
   checkLocalExport(id: N.Identifier) {
-    // scope.functions must be empty as Module code is always strict.
     if (
       this.scopeStack[0].lexical.indexOf(id.name) === -1 &&
-      this.scopeStack[0].var.indexOf(id.name) === -1
+      this.scopeStack[0].var.indexOf(id.name) === -1 &&
+      // In strict mode, scope.functions will always be empty.
+      // Modules are strict by default, but the `scriptMode` option
+      // can overwrite this behavior.
+      this.scopeStack[0].functions.indexOf(id.name) === -1
     ) {
       this.undefinedExports.set(id.name, id.start);
     }
diff --git a/packages/babel-parser/test/fixtures/core/scope/undecl-export-function-loose-mode/input.js b/packages/babel-parser/test/fixtures/core/scope/undecl-export-function-loose-mode/input.js
new file mode 100644
index 0000000000..87d3720d82
--- /dev/null
+++ b/packages/babel-parser/test/fixtures/core/scope/undecl-export-function-loose-mode/input.js
@@ -0,0 +1,3 @@
+function a() {}
+
+export { a };
\ No newline at end of file
diff --git a/packages/babel-parser/test/fixtures/core/scope/undecl-export-function-loose-mode/options.json b/packages/babel-parser/test/fixtures/core/scope/undecl-export-function-loose-mode/options.json
new file mode 100644
index 0000000000..0580fdad26
--- /dev/null
+++ b/packages/babel-parser/test/fixtures/core/scope/undecl-export-function-loose-mode/options.json
@@ -0,0 +1,4 @@
+{
+  "sourceType": "module",
+  "strictMode": false
+}
diff --git a/packages/babel-parser/test/fixtures/core/scope/undecl-export-function-loose-mode/output.json b/packages/babel-parser/test/fixtures/core/scope/undecl-export-function-loose-mode/output.json
new file mode 100644
index 0000000000..e59b53b2e0
--- /dev/null
+++ b/packages/babel-parser/test/fixtures/core/scope/undecl-export-function-loose-mode/output.json
@@ -0,0 +1,155 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 30,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 3,
+      "column": 13
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 30,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 3,
+        "column": 13
+      }
+    },
+    "sourceType": "module",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "FunctionDeclaration",
+        "start": 0,
+        "end": 15,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 15
+          }
+        },
+        "id": {
+          "type": "Identifier",
+          "start": 9,
+          "end": 10,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 9
+            },
+            "end": {
+              "line": 1,
+              "column": 10
+            },
+            "identifierName": "a"
+          },
+          "name": "a"
+        },
+        "generator": false,
+        "async": false,
+        "params": [],
+        "body": {
+          "type": "BlockStatement",
+          "start": 13,
+          "end": 15,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 13
+            },
+            "end": {
+              "line": 1,
+              "column": 15
+            }
+          },
+          "body": [],
+          "directives": []
+        }
+      },
+      {
+        "type": "ExportNamedDeclaration",
+        "start": 17,
+        "end": 30,
+        "loc": {
+          "start": {
+            "line": 3,
+            "column": 0
+          },
+          "end": {
+            "line": 3,
+            "column": 13
+          }
+        },
+        "specifiers": [
+          {
+            "type": "ExportSpecifier",
+            "start": 26,
+            "end": 27,
+            "loc": {
+              "start": {
+                "line": 3,
+                "column": 9
+              },
+              "end": {
+                "line": 3,
+                "column": 10
+              }
+            },
+            "local": {
+              "type": "Identifier",
+              "start": 26,
+              "end": 27,
+              "loc": {
+                "start": {
+                  "line": 3,
+                  "column": 9
+                },
+                "end": {
+                  "line": 3,
+                  "column": 10
+                },
+                "identifierName": "a"
+              },
+              "name": "a"
+            },
+            "exported": {
+              "type": "Identifier",
+              "start": 26,
+              "end": 27,
+              "loc": {
+                "start": {
+                  "line": 3,
+                  "column": 9
+                },
+                "end": {
+                  "line": 3,
+                  "column": 10
+                },
+                "identifierName": "a"
+              },
+              "name": "a"
+            }
+          }
+        ],
+        "source": null,
+        "declaration": null
+      }
+    ],
+    "directives": []
+  }
+}
\ No newline at end of file