diff --git a/lib/base/scriptutils.cpp b/lib/base/scriptutils.cpp
index 5f5a08bdd..1109a2729 100644
--- a/lib/base/scriptutils.cpp
+++ b/lib/base/scriptutils.cpp
@@ -156,7 +156,7 @@ void ScriptUtils::Log(const std::vector<Value>& arguments)
 		message = arguments[2];
 	}
 
-	if (message.IsString() || !message.IsObjectType<Array>() && !message.IsObjectType<Dictionary>())
+	if (message.IsString() || (!message.IsObjectType<Array>() && !message.IsObjectType<Dictionary>()))
 		::Log(severity, facility, message);
 	else
 		::Log(severity, facility, JsonEncode(message));
diff --git a/lib/config/expression.cpp b/lib/config/expression.cpp
index bd5bb7852..da9e32f1f 100644
--- a/lib/config/expression.cpp
+++ b/lib/config/expression.cpp
@@ -352,6 +352,8 @@ Value ConditionalExpression::DoEvaluate(VMFrame& frame, DebugHint *dhint) const
 		return m_TrueBranch->Evaluate(frame, dhint);
 	else if (m_FalseBranch)
 		return m_FalseBranch->Evaluate(frame, dhint);
+
+	return Empty;
 }
 
 Value ReturnExpression::DoEvaluate(VMFrame& frame, DebugHint *dhint) const
diff --git a/lib/icinga/dependency.hpp b/lib/icinga/dependency.hpp
index afea95920..27d0c5d8d 100644
--- a/lib/icinga/dependency.hpp
+++ b/lib/icinga/dependency.hpp
@@ -28,7 +28,7 @@ namespace icinga
 {
 
 class ApplyRule;
-class VMFrame;
+struct VMFrame;
 class Host;
 class Service;
 
diff --git a/lib/icinga/notification.hpp b/lib/icinga/notification.hpp
index 4bc864331..3c1457e1f 100644
--- a/lib/icinga/notification.hpp
+++ b/lib/icinga/notification.hpp
@@ -68,7 +68,7 @@ enum NotificationType
 class NotificationCommand;
 class Checkable;
 class ApplyRule;
-class VMFrame;
+struct VMFrame;
 class Host;
 class Service;
 
diff --git a/lib/icinga/scheduleddowntime.hpp b/lib/icinga/scheduleddowntime.hpp
index 45fb63f3f..5a709686c 100644
--- a/lib/icinga/scheduleddowntime.hpp
+++ b/lib/icinga/scheduleddowntime.hpp
@@ -29,7 +29,7 @@ namespace icinga
 {
 
 class ApplyRule;
-class VMFrame;
+struct VMFrame;
 class Host;
 class Service;