diff --git a/GUI/extensions.cpp b/GUI/extensions.cpp
index 4fb6b64..883f454 100644
--- a/GUI/extensions.cpp
+++ b/GUI/extensions.cpp
@@ -35,16 +35,13 @@ bool DispatchSentenceToExtensions(std::wstring& sentence, std::unordered_map<std
 	InfoForExtension* miscInfoTraverser = miscInfoLinkedList;
 	for (auto& i : miscInfo) miscInfoTraverser = miscInfoTraverser->nextProperty = new InfoForExtension{ i.first.c_str(), i.second, nullptr };
 	std::shared_lock<std::shared_mutex> extenLock(extenMutex);
-	try
+	for (auto i : extensions)
 	{
-		for (auto i : extensions)
-		{
-			wchar_t* prev = sentenceBuffer;
-			sentenceBuffer = i.second(sentenceBuffer, miscInfoLinkedList);
-			if (sentenceBuffer != prev) HeapFree(GetProcessHeap(), 0, prev);
-		}
+		wchar_t* nextBuffer = i.second(sentenceBuffer, miscInfoLinkedList);
+		if (nextBuffer == nullptr) { success = false; break; }
+		if (nextBuffer != sentenceBuffer) HeapFree(GetProcessHeap(), 0, sentenceBuffer);
+		sentenceBuffer = nextBuffer;
 	}
-	catch (...) { success = false; }
 	sentence = std::wstring(sentenceBuffer);
 	HeapFree(GetProcessHeap(), 0, sentenceBuffer);
 	delete miscInfoLinkedList;
diff --git a/extensions/extensions.h b/extensions/extensions.h
index 2c61a87..f01f3dd 100644
--- a/extensions/extensions.h
+++ b/extensions/extensions.h
@@ -23,6 +23,8 @@ struct SentenceInfo
 	}
 };
 
+struct InvalidSentence {};
+
 bool ProcessSentence(std::wstring& sentence, SentenceInfo sentenceInfo);
 
 /**
@@ -31,20 +33,24 @@ bool ProcessSentence(std::wstring& sentence, SentenceInfo sentenceInfo);
 	* You should not modify this sentence. If you want Textractor to receive a modified sentence, copy it into your own buffer and return that.
 	* Please allocate the buffer using HeapAlloc() and not new[] or malloc() or something else: Textractor uses HeapFree() to free it.
 	* Param miscInfo: pointer to start of singly linked list containing misc info about the sentence.
-	* Return value: pointer to sentence Textractor takes for future processing and display.
+	* Return value: pointer to sentence Textractor takes for future processing and display. If nullptr, Textractor will 'eat' the sentence.
 	* Return 'sentence' unless you created a new sentence/buffer as mentioned above.
 	* Textractor will display the sentence after all extensions have had a chance to process and/or modify it.
 	* THIS FUNCTION MAY BE RUN SEVERAL TIMES CONCURRENTLY: PLEASE ENSURE THAT IT IS THREAD SAFE!
 */
-extern "C" __declspec(dllexport) const wchar_t* OnNewSentence(const wchar_t* sentenceArr, const InfoForExtension* miscInfo)
+extern "C" __declspec(dllexport) const wchar_t* OnNewSentence(const wchar_t* sentence, const InfoForExtension* miscInfo)
 {
-	std::wstring sentence(sentenceArr);
-	if (ProcessSentence(sentence, SentenceInfo{ miscInfo }))
+	try
 	{
-		// No need to worry about freeing this: Textractor does it for you.
-		wchar_t* newSentence = (wchar_t*)HeapAlloc(GetProcessHeap(), 0, (sentence.size() + 1) * sizeof(wchar_t));
-		wcscpy_s(newSentence, sentence.size() + 1, sentence.c_str());
-		return newSentence;
+		std::wstring sentenceStr(sentence);
+		if (ProcessSentence(sentenceStr, SentenceInfo{ miscInfo }))
+		{
+			// No need to worry about freeing this: Textractor does it for you.
+			wchar_t* newSentence = (wchar_t*)HeapAlloc(GetProcessHeap(), 0, (sentenceStr.size() + 1) * sizeof(wchar_t));
+			wcscpy_s(newSentence, sentenceStr.size() + 1, sentenceStr.c_str());
+			return newSentence;
+		}
+		else return sentence;
 	}
-	else return sentenceArr;
+	catch (InvalidSentence) { return nullptr; }
 }
diff --git a/extensions/removerepeat.cpp b/extensions/removerepeat.cpp
index c02919c..09996bc 100644
--- a/extensions/removerepeat.cpp
+++ b/extensions/removerepeat.cpp
@@ -25,7 +25,7 @@ bool RemoveRepeatedChars(std::wstring& sentence)
 
 bool RemoveCyclicRepeats(std::wstring& sentence)
 {
-	if (sentence == L"") throw std::exception();
+	if (sentence == L"") throw InvalidSentence();
 	int junkLength = 0;
 	wchar_t junk[2000] = {};
 	while (wcsstr(sentence.c_str() + junkLength, junk))
@@ -47,7 +47,7 @@ bool RemoveRepeatedSentences(std::wstring& sentence, int64_t handle)
 	static std::set<std::pair<int64_t, std::wstring>> seenSentences;
 	static std::mutex m;
 	std::lock_guard<std::mutex> l(m);
-	if (seenSentences.count({ handle, sentence }) != 0) throw std::exception();
+	if (seenSentences.count({ handle, sentence }) != 0) throw InvalidSentence();
 	seenSentences.insert({ handle, sentence });
 	return false;
 }