diff --git a/source/fab/tools/linker.py b/source/fab/tools/linker.py
index 6b62fd45..5b8b474b 100644
--- a/source/fab/tools/linker.py
+++ b/source/fab/tools/linker.py
@@ -9,7 +9,7 @@
 
 import os
 from pathlib import Path
-from typing import cast, List, Optional
+from typing import cast, Dict, List, Optional
 
 from fab.tools.category import Category
 from fab.tools.compiler import Compiler
@@ -52,7 +52,7 @@ def __init__(self, name: Optional[str] = None,
         self.flags.extend(os.getenv("LDFLAGS", "").split())
 
         # Maintain a set of flags for common libraries.
-        self._lib_flags: dict[str, List[str]] = {}
+        self._lib_flags: Dict[str, List[str]] = {}
         # Include netcdf as an example, since it is reasonable portable
         self.add_lib_flags(
             'netcdf',