diff --git a/freqtrade/strategy/interface.py b/freqtrade/strategy/interface.py
index d8f379d53..1d6ca5ac8 100644
--- a/freqtrade/strategy/interface.py
+++ b/freqtrade/strategy/interface.py
@@ -161,7 +161,7 @@ class IStrategy(ABC):
         :param dataframe: Dataframe to analyze
         :return: (Buy, Sell) A bool-tuple indicating buy/sell signal
         """
-        if isinstance(dataframe, DataFrame) and dataframe.empty:
+        if not isinstance(dataframe, DataFrame) or dataframe.empty:
             logger.warning('Empty ticker history for pair %s', pair)
             return False, False
 
diff --git a/freqtrade/tests/strategy/test_interface.py b/freqtrade/tests/strategy/test_interface.py
index ffef568de..d42296462 100644
--- a/freqtrade/tests/strategy/test_interface.py
+++ b/freqtrade/tests/strategy/test_interface.py
@@ -49,6 +49,11 @@ def test_get_signal_empty(default_conf, mocker, caplog):
     assert (False, False) == _STRATEGY.get_signal('foo', default_conf['ticker_interval'],
                                                   DataFrame())
     assert log_has('Empty ticker history for pair foo', caplog.record_tuples)
+    caplog.clear()
+
+    assert (False, False) == _STRATEGY.get_signal('bar', default_conf['ticker_interval'],
+                                                  [])
+    assert log_has('Empty ticker history for pair bar', caplog.record_tuples)
 
 
 def test_get_signal_exception_valueerror(default_conf, mocker, caplog, ticker_history):