diff --git a/src/libfetchers/path.cc b/src/libfetchers/path.cc
index fca0df84b..fe1534aba 100644
--- a/src/libfetchers/path.cc
+++ b/src/libfetchers/path.cc
@@ -157,7 +157,11 @@ struct PathInputScheme : InputScheme
             });
             storePath = store->addToStoreFromDump(*src, "source");
         }
-        input.attrs.insert_or_assign("lastModified", uint64_t(mtime));
+
+        /* Trust the lastModified value supplied by the user, if
+           any. It's not a "secure" attribute so we don't care. */
+        if (!input.getLastModified())
+            input.attrs.insert_or_assign("lastModified", uint64_t(mtime));
 
         return {makeStorePathAccessor(store, *storePath), std::move(input)};
     }
diff --git a/tests/functional/fetchPath.sh b/tests/functional/fetchPath.sh
index 560a270c1..1df895b61 100755
--- a/tests/functional/fetchPath.sh
+++ b/tests/functional/fetchPath.sh
@@ -6,3 +6,6 @@ touch "$TEST_ROOT/foo" -t 202211111111
 # We only check whether 2022-11-1* **:**:** is the last modified date since
 # `lastModified` is transformed into UTC in `builtins.fetchTarball`.
 [[ "$(nix eval --impure --raw --expr "(builtins.fetchTree \"path://$TEST_ROOT/foo\").lastModifiedDate")" =~ 2022111.* ]]
+
+# Check that we can override lastModified for "path:" inputs.
+[[ "$(nix eval --impure --expr "(builtins.fetchTree { type = \"path\"; path = \"$TEST_ROOT/foo\"; lastModified = 123; }).lastModified")" = 123 ]]