diff --git a/lib/config/configitem.cpp b/lib/config/configitem.cpp
index 17fe9da03..fbb59eb15 100644
--- a/lib/config/configitem.cpp
+++ b/lib/config/configitem.cpp
@@ -381,6 +381,7 @@ bool ConfigItem::ActivateItems(void)
 	}
 
 	upq.Join();
+	upq.ReportExceptions("ConfigItem");
 
 #ifdef I2_DEBUG
 	BOOST_FOREACH(const DynamicType::Ptr& type, DynamicType::GetTypes()) {
diff --git a/lib/icinga/legacytimeperiod.cpp b/lib/icinga/legacytimeperiod.cpp
index 0ef798991..6e380ad8c 100644
--- a/lib/icinga/legacytimeperiod.cpp
+++ b/lib/icinga/legacytimeperiod.cpp
@@ -379,6 +379,9 @@ void LegacyTimePeriod::ProcessTimeRanges(const String& timeranges, tm *reference
 
 	BOOST_FOREACH(const String& range, ranges) {
 		Dictionary::Ptr segment = ProcessTimeRange(range, reference);
+		if (segment->Get("begin") >= segment->Get("end"))
+			BOOST_THROW_EXCEPTION(std::invalid_argument("Time period segment ends before it begins"));
+
 		result->Add(segment);
 	}
 }