diff --git a/src/devx/make/devx.mak b/src/devx/make/devx.mak
index 469a879..8677d78 100644
--- a/src/devx/make/devx.mak
+++ b/src/devx/make/devx.mak
@@ -385,7 +385,7 @@ devx-check-test-speed:
 # This is also automatically enforced by the pytest plugin (pytest11 entry point).
 # Use this target for CI gates or pre-commit hooks.
 devx-check-test-isolation:
-	@$(DEVX_PYTHON) -m devx.tools.check_test_isolation --test-path $(DEVX_TEST_PATHS)
+	@$(DEVX_PYTHON) -m devx.tools.check_test_isolation $(addprefix --test-path ,$(DEVX_TEST_PATHS))
 
 # Check translation files for missing keys, dead keys, and missing languages.
 # Runs automatically as part of devx-lint to shift-left translation issues
diff --git a/src/devx/tools/check_test_isolation.py b/src/devx/tools/check_test_isolation.py
index e27ae3c..eea8723 100644
--- a/src/devx/tools/check_test_isolation.py
+++ b/src/devx/tools/check_test_isolation.py
@@ -449,10 +449,12 @@ def pytest_collection_finish(session):  # type: ignore[no-untyped-def]  # pragma
 @click.command()
 @click.option(
     "--test-path",
+    "test_paths",
     type=click.Path(exists=True, path_type=Path),
-    default=Path("tests/"),
+    multiple=True,
+    default=[Path("tests/")],
     show_default=True,
-    help="Path to test directory or file to analyze.",
+    help="Path to test directory or file to analyze (can be specified multiple times).",
 )
 @click.option(
     "--max-loop-iterations",
@@ -474,31 +476,35 @@ def pytest_collection_finish(session):  # type: ignore[no-untyped-def]  # pragma
     help="Comma-separated list of categories to check (default: all). "
     "Available: unpatched-subprocess, unpatched-sleep, unpatched-helper, excessive-iterations",
 )
-def cli(test_path: Path, max_loop_iterations: int, strict: bool, categories: str) -> None:
+def cli(test_paths: tuple[Path, ...], max_loop_iterations: int, strict: bool, categories: str) -> None:
     """Check test files for un-hermetic patterns that cause slow or flaky tests."""
     allowed: set[str] | None = None
     if categories:
         allowed = {c.strip() for c in categories.split(",")}
 
-    violations = analyze_test_files(test_path, max_loop_iterations, allowed)
+    all_violations: list[Violation] = []
+    total_files = 0
+    for test_path in test_paths:
+        violations = analyze_test_files(test_path, max_loop_iterations, allowed)
+        all_violations.extend(violations)
+        total_files += len(find_test_files(test_path))
 
-    if not violations:
-        file_count = len(find_test_files(test_path))
+    if not all_violations:
         click.echo(
-            _("Test isolation check passed: {count} test files analyzed, no violations found.", count=file_count)
+            _("Test isolation check passed: {count} test files analyzed, no violations found.", count=total_files)
         )
         sys.exit(0)
 
     click.echo(
         _(
             "Test isolation check FAILED: {count} violation(s) found in {files} test file(s).",
-            count=len(violations),
-            files=len({v.file for v in violations}),
+            count=len(all_violations),
+            files=len({v.file for v in all_violations}),
         ),
         err=True,
     )
     click.echo("")
-    for v in sorted(violations, key=lambda x: (str(x.file), x.line)):
+    for v in sorted(all_violations, key=lambda x: (str(x.file), x.line)):
         click.echo(f"  {v.format()}", err=True)
 
     click.echo("")