diff --git a/python/tach/check_external.py b/python/tach/check_external.py
index 5e66a08f..92ad602b 100644
--- a/python/tach/check_external.py
+++ b/python/tach/check_external.py
@@ -3,6 +3,7 @@
 from dataclasses import dataclass
 from typing import TYPE_CHECKING
 
+from tach.errors import TachError
 from tach.extension import check_external_dependencies, set_excluded_paths
 from tach.utils.external import get_module_mappings, is_stdlib_module
 
@@ -18,6 +19,17 @@ class ExternalCheckDiagnosticts:
     unused_dependencies: dict[str, list[str]]
 
 
+def extract_module_mappings(rename: list[str]) -> dict[str, list[str]]:
+    try:
+        return {
+            module: [name] for module, name in [module.split(":") for module in rename]
+        }
+    except ValueError as e:
+        raise TachError(
+            "Invalid rename format: expected format is a list of 'module:name' pairs, e.g. ['PIL:pillow']"
+        ) from e
+
+
 def check_external(
     project_root: Path,
     project_config: ProjectConfig,
@@ -32,10 +44,15 @@ def check_external(
         use_regex_matching=project_config.use_regex_matching,
     )
 
+    metadata_module_mappings = get_module_mappings()
+    if project_config.external.rename:
+        metadata_module_mappings.update(
+            extract_module_mappings(project_config.external.rename)
+        )
     diagnostics = check_external_dependencies(
         project_root=str(project_root),
         source_roots=serialized_source_roots,
-        module_mappings=get_module_mappings(),
+        module_mappings=metadata_module_mappings,
         ignore_type_checking_imports=project_config.ignore_type_checking_imports,
     )
     undeclared_dependencies_by_file = diagnostics[0]
diff --git a/python/tach/cli.py b/python/tach/cli.py
index 09aab412..d9cbc06f 100644
--- a/python/tach/cli.py
+++ b/python/tach/cli.py
@@ -223,7 +223,7 @@ def print_unused_external_dependencies(
     for pyproject_path, dependencies in unused_dependencies.items():
         if dependencies:
             print(
-                f"{icons.WARNING} {BCOLORS.WARNING}Unused dependencies from project at {BCOLORS.OKCYAN}'{pyproject_path}'{BCOLORS.ENDC}{BCOLORS.ENDC}:"
+                f"{icons.WARNING}  {BCOLORS.WARNING}Unused dependencies from project at {BCOLORS.OKCYAN}'{pyproject_path}'{BCOLORS.ENDC}{BCOLORS.ENDC}:"
             )
             for dependency in dependencies:
                 print(f"\t{BCOLORS.WARNING}{dependency}{BCOLORS.ENDC}")
diff --git a/python/tach/extension.pyi b/python/tach/extension.pyi
index af52e2b2..7d56438e 100644
--- a/python/tach/extension.pyi
+++ b/python/tach/extension.pyi
@@ -130,6 +130,7 @@ class CacheConfig:
 
 class ExternalDependencyConfig:
     exclude: list[str]
+    rename: list[str]
 
 class UnusedDependencies:
     path: str
diff --git a/src/core/config.rs b/src/core/config.rs
index 31e00a83..b01093a5 100644
--- a/src/core/config.rs
+++ b/src/core/config.rs
@@ -194,6 +194,8 @@ impl CacheConfig {
 pub struct ExternalDependencyConfig {
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     pub exclude: Vec<String>,
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub rename: Vec<String>,
 }
 
 impl ExternalDependencyConfig {