diff --git a/diceware/random_sources.py b/diceware/random_sources.py
index 2e3c8fd52d165f484867bd5b1603bd9f5e0336a4..e1e263dc0b3c79232e9aa932c7c5e3dc99ca7f4d 100644
--- a/diceware/random_sources.py
+++ b/diceware/random_sources.py
@@ -137,7 +137,11 @@ class RealDiceRandomSource(object):
             raise ValueError(
                 "Must provide at least %s items" % self.dice_sides)
         if (self.dice_sides ** num_rolls) < len(sequence):
-            print("Warning: entropy is reduced!")
+            print(
+                "Warning: entropy is reduced! Using only first %s of %s "
+                "words/items of your wordlist." % (
+                    self.dice_sides ** num_rolls, len(sequence))
+                  )
         print(
             "Please roll %s dice (or a single dice %s times)." % (
                 num_rolls, num_rolls))
diff --git a/tests/test_random_sources.py b/tests/test_random_sources.py
index 7895daeb1278a0aebb5b7babbf1a823b0104c14f..2c828a941b61f41618a11ea8f0523f3e18a7dab9 100644
--- a/tests/test_random_sources.py
+++ b/tests/test_random_sources.py
@@ -196,6 +196,7 @@ class TestRealDiceRandomSource(object):
         assert picked == 1
         out, err = capsys.readouterr()
         assert "entropy is reduced" in out
+        assert "Using only first 6 of 7 words" in out
         assert err == ""
 
     def test_no_hint_if_entropy_is_not_decreased(self, monkeypatch, capsys):