diff --git a/extensions/CMakeLists.txt b/extensions/CMakeLists.txt
index e645da1..95d8407 100644
--- a/extensions/CMakeLists.txt
+++ b/extensions/CMakeLists.txt
@@ -1,8 +1,8 @@
 cmake_policy(SET CMP0037 OLD)
 
-add_library(256_Remove\ Repetition SHARED removerepeat.cpp)
-add_library(512_Copy\ to\ Clipboard SHARED copyclipboard.cpp)
-add_library(1024_Google\ Translate SHARED googletranslate.cpp)
-add_library(2048_Extra\ Newlines SHARED extranewlines.cpp)
+add_library(256_Remove\ Repetition SHARED removerepeat.cpp extensionimpl.cpp)
+add_library(512_Copy\ to\ Clipboard SHARED copyclipboard.cpp extensionimpl.cpp)
+add_library(1024_Google\ Translate SHARED googletranslate.cpp extensionimpl.cpp)
+add_library(2048_Extra\ Newlines SHARED extranewlines.cpp extensionimpl.cpp)
 
 target_link_libraries(1024_Google\ Translate winhttp.lib)
\ No newline at end of file
diff --git a/extensions/copyclipboard.cpp b/extensions/copyclipboard.cpp
index 920d0f1..9b344f8 100644
--- a/extensions/copyclipboard.cpp
+++ b/extensions/copyclipboard.cpp
@@ -1,4 +1,4 @@
-#include "extensions.h"
+#include "extension.h"
 
 bool ProcessSentence(std::wstring& sentence, SentenceInfo sentenceInfo)
 {
diff --git a/extensions/extension.h b/extensions/extension.h
new file mode 100644
index 0000000..7731410
--- /dev/null
+++ b/extensions/extension.h
@@ -0,0 +1,27 @@
+#pragma once
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#include <cstdint>
+#include <string>
+
+struct InfoForExtension
+{
+	const char* name;
+	int64_t value;
+	InfoForExtension* next;
+};
+
+struct SentenceInfo
+{
+	const InfoForExtension* list;
+	// Traverse linked list to find info.
+	int64_t operator[](std::string propertyName)
+	{
+		for (auto i = list; i != nullptr; i = i->next) if (propertyName == i->name) return i->value;
+		throw;
+	}
+};
+
+struct SKIP {};
+inline void Skip() { throw SKIP(); }
diff --git a/extensions/extensions.h b/extensions/extensionimpl.cpp
similarity index 75%
rename from extensions/extensions.h
rename to extensions/extensionimpl.cpp
index 9b6e769..794d91b 100644
--- a/extensions/extensions.h
+++ b/extensions/extensionimpl.cpp
@@ -1,29 +1,4 @@
-#pragma once
-
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#include <cstdint>
-#include <string>
-
-struct InfoForExtension
-{
-	const char* name;
-	int64_t value;
-	InfoForExtension* next;
-};
-
-struct SentenceInfo
-{
-	const InfoForExtension* list;
-	// Traverse linked list to find info.
-	int64_t operator[](std::string propertyName)
-	{
-		for (auto i = list; i != nullptr; i = i->next) if (propertyName == i->name) return i->value;
-		throw;
-	}
-};
-
-struct InvalidSentence {};
+#include "extension.h"
 
 bool ProcessSentence(std::wstring& sentence, SentenceInfo sentenceInfo);
 
@@ -52,5 +27,5 @@ extern "C" __declspec(dllexport) const wchar_t* OnNewSentence(const wchar_t* sen
 		}
 		else return sentence;
 	}
-	catch (InvalidSentence) { return nullptr; }
+	catch (SKIP) { return nullptr; }
 }
diff --git a/extensions/extranewlines.cpp b/extensions/extranewlines.cpp
index 210c491..d0fb344 100644
--- a/extensions/extranewlines.cpp
+++ b/extensions/extranewlines.cpp
@@ -1,4 +1,4 @@
-#include "extensions.h"
+#include "extension.h"
 
 bool ProcessSentence(std::wstring& sentence, SentenceInfo sentenceInfo)
 {
diff --git a/extensions/googletranslate.cpp b/extensions/googletranslate.cpp
index a405196..44d4ff1 100644
--- a/extensions/googletranslate.cpp
+++ b/extensions/googletranslate.cpp
@@ -1,4 +1,4 @@
-#include "extensions.h"
+#include "extension.h"
 #include <winhttp.h>
 #include <ctime>
 #include <regex>
diff --git a/extensions/removerepeat.cpp b/extensions/removerepeat.cpp
index 09996bc..b0baa0a 100644
--- a/extensions/removerepeat.cpp
+++ b/extensions/removerepeat.cpp
@@ -1,4 +1,4 @@
-#include "extensions.h"
+#include "extension.h"
 #include <set>
 #include <mutex>
 
@@ -25,7 +25,7 @@ bool RemoveRepeatedChars(std::wstring& sentence)
 
 bool RemoveCyclicRepeats(std::wstring& sentence)
 {
-	if (sentence == L"") throw InvalidSentence();
+	if (sentence == L"") Skip();
 	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 InvalidSentence();
+	if (seenSentences.count({ handle, sentence }) != 0) Skip();
 	seenSentences.insert({ handle, sentence });
 	return false;
 }