diff --git a/src/dllmain.cpp b/src/dllmain.cpp
index d65ba2f..865a7b4 100644
--- a/src/dllmain.cpp
+++ b/src/dllmain.cpp
@@ -77,9 +77,9 @@ extern "C" NPPAUTODETECTINDENT_API void beNotified(SCNotification *notifyCode)
 
 		case NPPN_FILECLOSED:
 		{
-			const uptr_t id = notifyCode->nmhdr.idFrom;
-
-			indentCache.erase(id);
+			TCHAR path[MAX_PATH + 1] {};
+			myPlugin->message()->sendNppMessage<>(NPPM_GETFULLCURRENTPATH, MAX_PATH, reinterpret_cast<LPARAM>(path));
+			indentCache.erase(path);
 			break;
 		}
 
@@ -88,12 +88,12 @@ extern "C" NPPAUTODETECTINDENT_API void beNotified(SCNotification *notifyCode)
 			if (Settings::instance()->getDisablePlugin())
 				break;
 
-			const uptr_t id = notifyCode->nmhdr.idFrom;
+			TCHAR path[MAX_PATH + 1] {};
+			myPlugin->message()->sendNppMessage<>(NPPM_GETFULLCURRENTPATH, MAX_PATH, reinterpret_cast<LPARAM>(path));
 
-			const auto iter = indentCache.find(id);
+			const auto iter = indentCache.find(path);
 			const nppAutoDetectIndent::IndentInfo info = (iter != indentCache.end()) ? iter->second : nppAutoDetectIndent::detectIndentInfo();
-
-			indentCache[id] = info;
+			indentCache[path] = info;
 			applyIndentInfo(info);
 			break;
 		}
diff --git a/src/nppAutoDetectIndent.cpp b/src/nppAutoDetectIndent.cpp
index b3b859c..8390af5 100644
--- a/src/nppAutoDetectIndent.cpp
+++ b/src/nppAutoDetectIndent.cpp
@@ -21,7 +21,7 @@
 
 #include "settings.h"
 
-#define PLUGIN_VERSION "1.4"
+#define PLUGIN_VERSION "1.5"
 
 namespace
 {
@@ -141,10 +141,11 @@ namespace MenuAction
 		}
 		else
 		{
-			const int id = plugin->message()->sendNppMessage<int>(NPPM_GETCURRENTBUFFERID, 0, 0);
+			TCHAR path[MAX_PATH + 1] {};
+			plugin->message()->sendNppMessage<>(NPPM_GETFULLCURRENTPATH, MAX_PATH, reinterpret_cast<LPARAM>(path));
 			const nppAutoDetectIndent::IndentInfo info = nppAutoDetectIndent::detectIndentInfo();
 
-			plugin->indentCache[id] = info;
+			plugin->indentCache[path] = info;
 			applyIndentInfo(info);
 		}
 	}
diff --git a/src/nppAutoDetectIndent.h b/src/nppAutoDetectIndent.h
index 48f0a4d..f483799 100644
--- a/src/nppAutoDetectIndent.h
+++ b/src/nppAutoDetectIndent.h
@@ -45,7 +45,7 @@ namespace nppAutoDetectIndent
 	NppSettings detectNppSettings();
 	void applyNppSettings(const NppSettings &settings);
 
-	using IndentCache = std::unordered_map<uptr_t, IndentInfo>;  // <file name, IndentInfo>
+	using IndentCache = std::unordered_map<std::wstring, IndentInfo>;  // <full file path, IndentInfo>
 }
 
 class MyPlugin