diff --git a/package.json b/package.json
index 46250135..6b53e5f6 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
         "color": "#ECECEC",
         "theme": "light"
     },
-    "version": "1.5.0",
+    "version": "1.5.1",
     "publisher": "salesforce",
     "license": "BSD-3-Clause",
     "engines": {
diff --git a/src/extension.ts b/src/extension.ts
index 87fa3e50..8525d935 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -67,8 +67,8 @@ export async function activate(context: vscode.ExtensionContext): Promise<SFCAEx
     const onDidSaveTextDocument = (listener: (e: unknown) => unknown): void => {
         context.subscriptions.push(vscode.workspace.onDidSaveTextDocument(listener));
     }
-    const onDidOpenTextDocument = (listener: (e: unknown) => unknown): void => {
-        context.subscriptions.push(vscode.workspace.onDidOpenTextDocument(listener));
+    const onDidChangeActiveTextEditor = (listener: (e: unknown) => unknown): void => {
+        context.subscriptions.push(vscode.window.onDidChangeActiveTextEditor(listener));
     }
 
     // Prepare utilities
@@ -84,6 +84,9 @@ export async function activate(context: vscode.ExtensionContext): Promise<SFCAEx
     const diagnosticManager: DiagnosticManager = new DiagnosticManagerImpl(diagnosticCollection, telemetryService, logger);
     context.subscriptions.push(diagnosticManager);
     const codeAnalyzerRunner: CodeAnalyzerRunner = new CodeAnalyzerRunner(diagnosticManager, settingsManager, telemetryService, logger);
+    const scanMonitor: ScanMonitor = new ScanMonitor();
+    context.subscriptions.push(scanMonitor);
+
 
     // We need to do this first in case any other services need access to those provided by the core extension.
     // TODO: Soon we should get rid of this CoreExtensionService stuff in favor of putting things inside of the ExternalServiceProvider
@@ -108,16 +111,25 @@ export async function activate(context: vscode.ExtensionContext): Promise<SFCAEx
 
         return codeAnalyzerRunner.runAndDisplay(Constants.COMMAND_RUN_ON_ACTIVE_FILE, [document.fileName]);
     });
-    // ... also invoked by opening a file if the user has set things to do so.
-    onDidOpenTextDocument(async (textDocument: vscode.TextDocument) => {
-        if (settingsManager.getAnalyzeOnOpen() && _isValidFileForAnalysis(textDocument.uri)) {
-            await codeAnalyzerRunner.runAndDisplay(Constants.COMMAND_RUN_ON_ACTIVE_FILE, [textDocument.fileName]);
+
+    onDidChangeActiveTextEditor(async (editor: vscode.TextEditor) => {
+        const shouldScan: boolean = editor !== undefined && editor.document.uri.scheme === 'file' && settingsManager.getAnalyzeOnOpen() &&
+            _isValidFileForAnalysis(editor.document.uri) && !scanMonitor.haveAlreadyScannedFile(editor.document.fileName);
+        if (shouldScan) {
+            scanMonitor.addFileToAlreadyScannedFiles(editor.document.fileName);
+            await codeAnalyzerRunner.runAndDisplay(Constants.COMMAND_RUN_ON_ACTIVE_FILE, [editor.document.fileName]);
         }
     });
-    // ... also invoked by saving a file if the user has set things to do so.
-    onDidSaveTextDocument(async (textDocument: vscode.TextDocument) => {
-        if (settingsManager.getAnalyzeOnSave() && _isValidFileForAnalysis(textDocument.uri)) {
-            await codeAnalyzerRunner.runAndDisplay(Constants.COMMAND_RUN_ON_ACTIVE_FILE, [textDocument.fileName]);
+
+    onDidSaveTextDocument(async (document: vscode.TextDocument) => {
+        if (document !== undefined && document.uri.scheme === 'file') {
+            scanMonitor.removeFileFromAlreadyScannedFiles(document.fileName);
+
+            const shouldScan: boolean = settingsManager.getAnalyzeOnSave() && _isValidFileForAnalysis(document.uri);
+            if (shouldScan) {
+                scanMonitor.addFileToAlreadyScannedFiles(document.fileName);
+                await codeAnalyzerRunner.runAndDisplay(Constants.COMMAND_RUN_ON_ACTIVE_FILE, [document.fileName]);
+            }
         }
     });
 
@@ -295,8 +307,10 @@ export async function activate(context: vscode.ExtensionContext): Promise<SFCAEx
         // Work Around: For reject & reject all, we really should be restoring the diagnostic that we removed
         // but CodeGenie doesn't let us keep the diagnostic information around at this point. So instead we must
         // rerun the scan instead to get the diagnostic restored.
-        await document.save(); // TODO: saving the document should be built in to the runAndDisplay command in my opinion
-        return codeAnalyzerRunner.runAndDisplay(Constants.COMMAND_RUN_ON_ACTIVE_FILE, [document.fileName]);
+        await document.save(); // TODO: This whole space will be refactored soon so that we don't need to do a save and rerun.
+        if (!settingsManager.getAnalyzeOnSave()) {
+            return codeAnalyzerRunner.runAndDisplay(Constants.COMMAND_RUN_ON_ACTIVE_FILE, [document.fileName]);
+        }
     });
 
     // Invoked by the "Accept All" button on the CodeGenie Unified Diff tool
@@ -322,8 +336,10 @@ export async function activate(context: vscode.ExtensionContext): Promise<SFCAEx
         // Work Around: For reject & reject all, we really should be restoring the diagnostic that we removed
         // but CodeGenie doesn't let us keep the diagnostic information around at this point. So instead we must
         // rerun the scan instead to get the diagnostic restored.
-        await document.save(); // TODO: saving the document should be built in to the runAndDisplay command in my opinion
-        return codeAnalyzerRunner.runAndDisplay(Constants.COMMAND_RUN_ON_ACTIVE_FILE, [document.fileName]);
+        await document.save(); // TODO: This whole space will be refactored soon so that we don't need to do a save and rerun.
+        if (!settingsManager.getAnalyzeOnSave()) {
+            return codeAnalyzerRunner.runAndDisplay(Constants.COMMAND_RUN_ON_ACTIVE_FILE, [document.fileName]);
+        }
     });
 
 
@@ -364,7 +380,7 @@ export function deactivate(): void {
 //       ....files. So We might not be able to get this perfect. Need to discuss this soon.
 export function _isValidFileForAnalysis(documentUri: vscode.Uri): boolean {
     const allowedFileTypes:string[] = ['.cls', '.js', '.apex', '.trigger', '.ts'];
-    return allowedFileTypes.includes(path.extname(documentUri.path));
+    return allowedFileTypes.includes(path.extname(documentUri.fsPath));
 }
 
 // Inside our package.json you'll see things like:
@@ -376,4 +392,24 @@ async function establishVariableInContext(varUsedInPackageJson: string, getValue
     vscode.workspace.onDidChangeConfiguration(async () => {
         await vscode.commands.executeCommand('setContext', varUsedInPackageJson, await getValueFcn());
     });
+}
+
+class ScanMonitor implements vscode.Disposable {
+    private alreadyScannedFiles: Set<string> = new Set();
+
+    haveAlreadyScannedFile(file: string): boolean {
+        return this.alreadyScannedFiles.has(file);
+    }
+    
+    removeFileFromAlreadyScannedFiles(file: string): void {
+        this.alreadyScannedFiles.delete(file);
+    }
+    
+    addFileToAlreadyScannedFiles(file: string) {
+        this.alreadyScannedFiles.add(file);
+    }
+
+    public dispose(): void {
+        this.alreadyScannedFiles.clear();
+    }
 }
\ No newline at end of file
diff --git a/src/test/legacy/scanner.test.ts b/src/test/legacy/scanner.test.ts
index fb71f0d4..3ea9fed6 100644
--- a/src/test/legacy/scanner.test.ts
+++ b/src/test/legacy/scanner.test.ts
@@ -344,7 +344,7 @@ suite('ScanRunner', () => {
 
         test('Adds process Id to the cache', () => {
             // ===== SETUP =====
-            const args:string[] = [];
+            const args:string[] = ['scanner', 'run', 'dfa', '--target', 'doesNotMatter', '--json'];
             const scanner = new ScanRunner();
             void context.workspaceState.update(Constants.WORKSPACE_DFA_PROCESS, undefined);