diff --git a/lib/icingadb/icingadb-objects.cpp b/lib/icingadb/icingadb-objects.cpp
index 56b74a3c1..da9b94ed3 100644
--- a/lib/icingadb/icingadb-objects.cpp
+++ b/lib/icingadb/icingadb-objects.cpp
@@ -1684,7 +1684,7 @@ bool IcingaDB::PrepareObject(const ConfigObject::Ptr& object, Dictionary::Ptr& a
 
 		attributes->Set("author", comment->GetAuthor());
 		attributes->Set("text", comment->GetText());
-		attributes->Set("entry_type", comment->GetEntryType());
+		attributes->Set("entry_type", IcingaDB::CommentTypeToString(comment->GetEntryType()));
 		attributes->Set("entry_time", TimestampToMilliseconds(comment->GetEntryTime()));
 		attributes->Set("is_persistent", comment->GetPersistent());
 		attributes->Set("is_sticky", comment->GetSticky());
@@ -2300,7 +2300,7 @@ void IcingaDB::SendAddedComment(const Comment::Ptr& comment)
 		"entry_time", Convert::ToString(TimestampToMilliseconds(comment->GetEntryTime())),
 		"author", Utility::ValidateUTF8(comment->GetAuthor()),
 		"comment", Utility::ValidateUTF8(comment->GetText()),
-		"entry_type", Convert::ToString(comment->GetEntryType()),
+		"entry_type", IcingaDB::CommentTypeToString(comment->GetEntryType()),
 		"is_persistent", Convert::ToString((unsigned short)comment->GetPersistent()),
 		"is_sticky", Convert::ToString((unsigned short)comment->GetSticky()),
 		"event_id", CalcEventID("comment_add", comment),
@@ -2372,7 +2372,7 @@ void IcingaDB::SendRemovedComment(const Comment::Ptr& comment)
 		"entry_time", Convert::ToString(TimestampToMilliseconds(comment->GetEntryTime())),
 		"author", Utility::ValidateUTF8(comment->GetAuthor()),
 		"comment", Utility::ValidateUTF8(comment->GetText()),
-		"entry_type", Convert::ToString(comment->GetEntryType()),
+		"entry_type", IcingaDB::CommentTypeToString(comment->GetEntryType()),
 		"is_persistent", Convert::ToString((unsigned short)comment->GetPersistent()),
 		"is_sticky", Convert::ToString((unsigned short)comment->GetSticky()),
 		"event_id", CalcEventID("comment_remove", comment),
diff --git a/lib/icingadb/icingadb-utility.cpp b/lib/icingadb/icingadb-utility.cpp
index 89e5a5031..a7ea8b47f 100644
--- a/lib/icingadb/icingadb-utility.cpp
+++ b/lib/icingadb/icingadb-utility.cpp
@@ -245,6 +245,21 @@ const char* IcingaDB::GetNotificationTypeByEnum(NotificationType type)
 	VERIFY(!"Invalid notification type.");
 }
 
+/**
+ * Converts the given comment type to its string representation.
+ *
+ * @ingroup icinga
+ */
+String IcingaDB::CommentTypeToString(CommentType type)
+{
+	switch (type) {
+		case CommentUser: return "comment";
+		case CommentAcknowledgement: return "ack";
+		default:
+			BOOST_THROW_EXCEPTION(std::invalid_argument("Invalid comment type specified"));
+	}
+}
+
 static const std::set<String> propertiesBlacklistEmpty;
 
 String IcingaDB::HashValue(const Value& value)
diff --git a/lib/icingadb/icingadb.hpp b/lib/icingadb/icingadb.hpp
index af58a977d..34bad080d 100644
--- a/lib/icingadb/icingadb.hpp
+++ b/lib/icingadb/icingadb.hpp
@@ -174,6 +174,7 @@ private:
 	static String GetObjectIdentifier(const ConfigObject::Ptr& object);
 	static String CalcEventID(const char* eventType, const ConfigObject::Ptr& object, double eventTime = 0, NotificationType nt = NotificationType(0));
 	static const char* GetNotificationTypeByEnum(NotificationType type);
+	static String CommentTypeToString(CommentType type);
 	static Dictionary::Ptr SerializeVars(const Dictionary::Ptr& vars);
 	static Dictionary::Ptr SerializeDependencyEdgeState(const DependencyGroup::Ptr& dependencyGroup, const Dependency::Ptr& dep);
 	static Dictionary::Ptr SerializeRedundancyGroupState(const Checkable::Ptr& child, const DependencyGroup::Ptr& redundancyGroup);