diff --git a/lib/techniques/error/use.py b/lib/techniques/error/use.py
index ab394b2ec..5bb18b785 100644
--- a/lib/techniques/error/use.py
+++ b/lib/techniques/error/use.py
@@ -304,7 +304,8 @@ def errorUse(expression, expected=None, dump=False):
                     warnMsg = "the SQL query provided does not "
                     warnMsg += "return any output"
                     logger.warn(warnMsg)
-
+                else:
+                    outputs = []  # for empty tables
                 return outputs
 
             if " ORDER BY " in expression and (stopLimit - startLimit) > SLOW_ORDER_COUNT_THRESHOLD:
diff --git a/lib/techniques/union/use.py b/lib/techniques/union/use.py
index 102d40762..853272ee3 100644
--- a/lib/techniques/union/use.py
+++ b/lib/techniques/union/use.py
@@ -263,7 +263,8 @@ def unionUse(expression, unpack=True, dump=False):
                     warnMsg = "the SQL query provided does not "
                     warnMsg += "return any output"
                     logger.warn(warnMsg)
-
+                else:
+                    value = []  # for empty tables
                 return value
 
             threadData = getCurrentThreadData()