diff --git a/lib/icinga/externalcommandprocessor.cpp b/lib/icinga/externalcommandprocessor.cpp
index e5ce06d59..dc4e04aad 100644
--- a/lib/icinga/externalcommandprocessor.cpp
+++ b/lib/icinga/externalcommandprocessor.cpp
@@ -492,7 +492,7 @@ void ExternalCommandProcessor::AcknowledgeSvcProblem(double, const std::vector<S
 
 	Log(LogInformation, "icinga", "Setting acknowledgement for service '" + service->GetName() + "'");
 
-	service->AcknowledgeProblem(sticky ? AcknowledgementSticky : AcknowledgementNormal);
+	service->AcknowledgeProblem(arguments[5], arguments[6], sticky ? AcknowledgementSticky : AcknowledgementNormal);
 }
 
 void ExternalCommandProcessor::AcknowledgeSvcProblemExpire(double, const std::vector<String>& arguments)
@@ -510,7 +510,7 @@ void ExternalCommandProcessor::AcknowledgeSvcProblemExpire(double, const std::ve
 
 	Log(LogInformation, "icinga", "Setting timed acknowledgement for service '" + service->GetName() + "'");
 
-	service->AcknowledgeProblem(sticky ? AcknowledgementSticky : AcknowledgementNormal, timestamp);
+	service->AcknowledgeProblem(arguments[6], arguments[7], sticky ? AcknowledgementSticky : AcknowledgementNormal, timestamp);
 }
 
 void ExternalCommandProcessor::RemoveSvcAcknowledgement(double, const std::vector<String>& arguments)
@@ -540,7 +540,7 @@ void ExternalCommandProcessor::AcknowledgeHostProblem(double, const std::vector<
 		if (service->GetState() == StateOK)
 			BOOST_THROW_EXCEPTION(std::invalid_argument("The host '" + arguments[0] + "' is OK."));
 
-		service->AcknowledgeProblem(sticky ? AcknowledgementSticky : AcknowledgementNormal);
+		service->AcknowledgeProblem(arguments[4], arguments[5], sticky ? AcknowledgementSticky : AcknowledgementNormal);
 	}
 }
 
@@ -560,7 +560,7 @@ void ExternalCommandProcessor::AcknowledgeHostProblemExpire(double, const std::v
 		if (service->GetState() == StateOK)
 			BOOST_THROW_EXCEPTION(std::invalid_argument("The host '" + arguments[0] + "' is OK."));
 
-		service->AcknowledgeProblem(sticky ? AcknowledgementSticky : AcknowledgementNormal, timestamp);
+		service->AcknowledgeProblem(arguments[5], arguments[6], sticky ? AcknowledgementSticky : AcknowledgementNormal, timestamp);
 	}
 }
 
diff --git a/lib/icinga/service-check.cpp b/lib/icinga/service-check.cpp
index 4270d8a27..0ccb50662 100644
--- a/lib/icinga/service-check.cpp
+++ b/lib/icinga/service-check.cpp
@@ -397,6 +397,11 @@ void Service::ProcessCheckResult(const Dictionary::Ptr& cr)
 		call_eventhandler = true;
 	}
 
+	bool remove_acknowledgement_comments = false;
+
+	if (GetAcknowledgement() == AcknowledgementNone)
+		remove_acknowledgement_comments = true;
+
 	bool hardChange = (GetStateType() == StateTypeHard && old_stateType == StateTypeSoft);
 
 	if (old_state != GetState() && old_stateType == StateTypeHard && GetStateType() == StateTypeHard)
@@ -425,6 +430,9 @@ void Service::ProcessCheckResult(const Dictionary::Ptr& cr)
 
 	olock.Unlock();
 
+	if (remove_acknowledgement_comments)
+		RemoveCommentsByType(CommentAcknowledgement);
+
 	Dictionary::Ptr vars_after = boost::make_shared<Dictionary>();
 	vars_after->Set("state", GetState());
 	vars_after->Set("state_type", GetStateType());
diff --git a/lib/icinga/service-comment.cpp b/lib/icinga/service-comment.cpp
index 0a02be8bd..972b71c8d 100644
--- a/lib/icinga/service-comment.cpp
+++ b/lib/icinga/service-comment.cpp
@@ -239,6 +239,36 @@ void Service::RefreshCommentsCache(void)
 	}
 }
 
+void Service::RemoveCommentsByType(int type)
+{
+	Dictionary::Ptr comments = GetComments();
+
+	if (!comments)
+		return;
+
+	std::vector<String> removedComments;
+
+	{
+		ObjectLock olock(comments);
+
+		String id;
+		Dictionary::Ptr comment;
+		BOOST_FOREACH(tie(id, comment), comments) {
+			if (comment->Get("entry_type") == type)
+				removedComments.push_back(id);
+		}
+	}
+
+	if (!removedComments.empty()) {
+		BOOST_FOREACH(const String& id, removedComments) {
+			comments->Remove(id);
+		}
+
+		ObjectLock olock(this);
+		Touch("comments");
+	}
+}
+
 void Service::RemoveExpiredComments(void)
 {
 	Dictionary::Ptr comments = GetComments();
diff --git a/lib/icinga/service.cpp b/lib/icinga/service.cpp
index 4bd5aeda1..76dc134ce 100644
--- a/lib/icinga/service.cpp
+++ b/lib/icinga/service.cpp
@@ -280,7 +280,7 @@ void Service::SetAcknowledgementExpiry(double timestamp)
 	Touch("acknowledgement_expiry");
 }
 
-void Service::AcknowledgeProblem(AcknowledgementType type, double expiry)
+void Service::AcknowledgeProblem(const String& author, const String& comment, AcknowledgementType type, double expiry)
 {
 	{
 		ObjectLock olock(this);
@@ -289,6 +289,8 @@ void Service::AcknowledgeProblem(AcknowledgementType type, double expiry)
 		SetAcknowledgementExpiry(expiry);
 	}
 
+	(void) AddComment(CommentAcknowledgement, author, comment, 0);
+
 	RequestNotifications(NotificationAcknowledgement, GetLastCheckResult());
 }
 
diff --git a/lib/icinga/service.h b/lib/icinga/service.h
index 0db3e4dd1..42d9489a0 100644
--- a/lib/icinga/service.h
+++ b/lib/icinga/service.h
@@ -162,7 +162,7 @@ public:
 
 	static void UpdateStatistics(const Dictionary::Ptr& cr);
 
-	void AcknowledgeProblem(AcknowledgementType type, double expiry = 0);
+	void AcknowledgeProblem(const String& author, const String& comment, AcknowledgementType type, double expiry = 0);
 	void ClearAcknowledgement(void);
 
 	void ExecuteCheck(void);
@@ -217,6 +217,7 @@ public:
 	    const String& text, double expireTime);
 
 	void RemoveAllComments(void);
+	void RemoveCommentsByType(int type);
 	static void RemoveComment(const String& id);
 
 	static String GetCommentIDFromLegacyID(int id);