diff --git a/pyhgtmap/main.py b/pyhgtmap/main.py
index a40b8a8..abd0fa8 100644
--- a/pyhgtmap/main.py
+++ b/pyhgtmap/main.py
@@ -492,17 +492,17 @@ def parseCommandLine(sys_args: List[str]) -> Tuple[Values, List[str]]:
                     opts.dataSource[opts.dataSource.index(s)] = "{0:s}v{1:.1f}".format(
                         s, opts.srtmVersion
                     )
-    else:
+    elif len(args) == 0:
+        # No explicit source nor input provided, try to download using default
         opts.dataSource = []
         if opts.viewfinder != 0:
             opts.dataSource.append("view{0:d}".format(opts.viewfinder))
         opts.dataSource.append(
             "srtm{0:d}v{1:.1f}".format(opts.srtmResolution, opts.srtmVersion)
         )
-        if not opts.area and not opts.polygon:
-            # this is a hint for makeOsmFilename() that files are specified on the
-            # command line
-            opts.dataSource = []
+    else:
+        # Input files provided, no download source
+        opts.dataSource = []
     needsEarthexplorerLogin = False
     for s in opts.dataSource:
         if s.startswith("srtm") and "v3" in s:
diff --git a/tests/test_main.py b/tests/test_main.py
index 2ca624a..2bdcbef 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -1,6 +1,6 @@
 import optparse
 import os
-from unittest.mock import patch
+from unittest.mock import MagicMock, patch
 from pyhgtmap import main
 
 from . import TEST_DATA_PATH
@@ -8,7 +8,9 @@
 
 @patch("pyhgtmap.main.NASASRTMUtil")
 @patch("pyhgtmap.main.HgtFilesProcessor")
-def test_main_download_from_poly(HgtFilesProcessor_mock, NASASRTMUtil_mock) -> None:
+def test_main_download_from_poly(
+    HgtFilesProcessor_mock: MagicMock, NASASRTMUtil_mock: MagicMock
+) -> None:
     """Only polygon option is used, without files; download tiles."""
     # Prepare
     sys_args = [
@@ -52,7 +54,9 @@ def test_main_download_from_poly(HgtFilesProcessor_mock, NASASRTMUtil_mock) -> N
 
 @patch("pyhgtmap.main.NASASRTMUtil")
 @patch("pyhgtmap.main.HgtFilesProcessor")
-def test_main_manual_input_poly(HgtFilesProcessor_mock, NASASRTMUtil_mock) -> None:
+def test_main_manual_input_poly(
+    HgtFilesProcessor_mock: MagicMock, NASASRTMUtil_mock: MagicMock
+) -> None:
     """Polygon option is used, with manual files; polygon must be applied to files."""
     # Prepare
     sys_args = [
@@ -80,9 +84,45 @@ def test_main_manual_input_poly(HgtFilesProcessor_mock, NASASRTMUtil_mock) -> No
     )
 
 
+@patch("pyhgtmap.main.configUtil")
 @patch("pyhgtmap.main.NASASRTMUtil")
 @patch("pyhgtmap.main.HgtFilesProcessor")
-def test_main_manual_input_no_poly(HgtFilesProcessor_mock, NASASRTMUtil_mock) -> None:
+def test_main_manual_input_poly_no_source(
+    HgtFilesProcessor_mock: MagicMock,
+    NASASRTMUtil_mock: MagicMock,
+    configUtil_mock: MagicMock,
+) -> None:
+    """Earthexplorer credentials shouldn't be required when providing tiles in input with a polygon."""
+    # Prepare
+    sys_args = [
+        f"--polygon={os.path.join(TEST_DATA_PATH, 'france.poly')}",
+        "N45E007.hgt",
+        "N46E007.hgt",
+        "N47E007.hgt",
+    ]
+
+    # Test
+    main.main_internal(sys_args)
+
+    # Check
+    configUtil_mock.Config.assert_not_called()
+    NASASRTMUtil_mock.getFiles.assert_not_called()
+
+    HgtFilesProcessor_mock.assert_called_once()
+    parsed_options: optparse.Values = HgtFilesProcessor_mock.call_args.args[3]
+    # area must be properly computed from files names
+    assert parsed_options.area == "7:45:8:48"
+    # Polygon check must be enabled for all files
+    HgtFilesProcessor_mock.return_value.process_files.assert_called_once_with(
+        [("N45E007.hgt", True), ("N46E007.hgt", True), ("N47E007.hgt", True)]
+    )
+
+
+@patch("pyhgtmap.main.NASASRTMUtil")
+@patch("pyhgtmap.main.HgtFilesProcessor")
+def test_main_manual_input_no_poly(
+    HgtFilesProcessor_mock: MagicMock, NASASRTMUtil_mock: MagicMock
+) -> None:
     """Polygon option is NOT used, with manual files."""
     # Prepare
     sys_args = [