diff --git a/src/vs/workbench/contrib/positronDataExplorerEditor/browser/positronDataExplorerActions.ts b/src/vs/workbench/contrib/positronDataExplorerEditor/browser/positronDataExplorerActions.ts
index 58915d7e2ff..df49c98b98d 100644
--- a/src/vs/workbench/contrib/positronDataExplorerEditor/browser/positronDataExplorerActions.ts
+++ b/src/vs/workbench/contrib/positronDataExplorerEditor/browser/positronDataExplorerActions.ts
@@ -21,7 +21,6 @@ import { PositronDataExplorerEditorInput } from './positronDataExplorerEditorInp
 import { POSITRON_DATA_EXPLORER_IS_ACTIVE_EDITOR, POSITRON_DATA_EXPLORER_IS_COLUMN_SORTING, POSITRON_DATA_EXPLORER_IS_PLAINTEXT, POSITRON_DATA_EXPLORER_LAYOUT } from './positronDataExplorerContextKeys.js';
 import { Codicon } from '../../../../base/common/codicons.js';
 import { PositronDataExplorerUri } from '../../../services/positronDataExplorer/common/positronDataExplorerUri.js';
-import { URI } from '../../../../base/common/uri.js';
 import { EditorOpenSource } from '../../../../platform/editor/common/editor.js';
 import { IPathService } from '../../../services/path/common/pathService.js';
 import { toLocalResource } from '../../../../base/common/resources.js';
@@ -750,22 +749,24 @@ class PositronDataExplorerOpenAsPlaintextAction extends Action2 {
 			return;
 		}
 
-		// Parse this URI - gives underlying FS URI if not memory-backed (scheme = duckdb)
-		const parsedDataExplorerURI = PositronDataExplorerUri.parse(originalURI);
-		if (!parsedDataExplorerURI) {
+		let backingUri = PositronDataExplorerUri.backingUri(originalURI);
+		if (!backingUri) {
 			return;
 		}
 
-		// Convert raw duckdb URI to appropriate file URI (scheme = file if local, vscode-remote if server)
-		const localURI = toLocalResource(
-			URI.parse(parsedDataExplorerURI),
-			environmentService.remoteAuthority,
-			pathService.defaultUriScheme
-		);
+		// Convert file URIs to the "local" scheme, i.e. vscode-remote when
+		// running as a server.
+		if (backingUri.scheme === 'file') {
+			backingUri = toLocalResource(
+				backingUri,
+				environmentService.remoteAuthority,
+				pathService.defaultUriScheme
+			);
+		}
 
 		// Invoke editor for file, using default editor (text) association
 		await editorService.openEditor({
-			resource: localURI,
+			resource: backingUri,
 			options: {
 				override: DEFAULT_EDITOR_ASSOCIATION.id,
 				source: EditorOpenSource.USER
diff --git a/src/vs/workbench/contrib/positronDataExplorerEditor/browser/positronDataExplorerEditor.contribution.ts b/src/vs/workbench/contrib/positronDataExplorerEditor/browser/positronDataExplorerEditor.contribution.ts
index dee71d57f89..16f2b1fd6bb 100644
--- a/src/vs/workbench/contrib/positronDataExplorerEditor/browser/positronDataExplorerEditor.contribution.ts
+++ b/src/vs/workbench/contrib/positronDataExplorerEditor/browser/positronDataExplorerEditor.contribution.ts
@@ -99,7 +99,7 @@ class PositronDataExplorerContribution extends Disposable {
 
 					// We create a data explorer URI that will use the DuckDB client
 					// that we just created.
-					const newResource = PositronDataExplorerUri.generate(`duckdb:${resource.path}`);
+					const newResource = PositronDataExplorerUri.generate(`duckdb:${resource.toString()}`);
 					return createDataExplorerEditor({
 						resource: newResource,
 						options
diff --git a/src/vs/workbench/contrib/positronDataExplorerEditor/browser/positronDataExplorerEditor.tsx b/src/vs/workbench/contrib/positronDataExplorerEditor/browser/positronDataExplorerEditor.tsx
index 6511a0d2ab5..68a37fe7ecb 100644
--- a/src/vs/workbench/contrib/positronDataExplorerEditor/browser/positronDataExplorerEditor.tsx
+++ b/src/vs/workbench/contrib/positronDataExplorerEditor/browser/positronDataExplorerEditor.tsx
@@ -36,7 +36,6 @@ import { IPositronDataExplorerService, PositronDataExplorerLayout } from '../../
 import { PositronDataExplorerEditorInput } from './positronDataExplorerEditorInput.js';
 import { PositronDataExplorerClosed, PositronDataExplorerClosedStatus } from '../../../browser/positronDataExplorer/components/dataExplorerClosed/positronDataExplorerClosed.js';
 import { POSITRON_DATA_EXPLORER_IS_COLUMN_SORTING, POSITRON_DATA_EXPLORER_IS_PLAINTEXT, POSITRON_DATA_EXPLORER_LAYOUT } from './positronDataExplorerContextKeys.js';
-import { URI } from '../../../../base/common/uri.js';
 
 /**
  * IPositronDataExplorerEditorOptions interface.
@@ -362,8 +361,8 @@ export class PositronDataExplorerEditor extends EditorPane implements IPositronD
 					positronDataExplorerInstance.tableDataDataGridInstance.isColumnSorting
 				);
 
-				const uri = URI.parse(this._identifier);
-				if (uri.scheme === 'duckdb') {
+				const uri = PositronDataExplorerUri.backingUri(input.resource);
+				if (uri) {
 					this._isPlaintextContextKey.set(PLAINTEXT_EXTS.some(ext => uri.path.endsWith(ext)));
 				} else {
 					this._isPlaintextContextKey.reset();
diff --git a/src/vs/workbench/services/positronDataExplorer/common/positronDataExplorerDuckDBBackend.ts b/src/vs/workbench/services/positronDataExplorer/common/positronDataExplorerDuckDBBackend.ts
index 181ce29f375..c6cb6c1639a 100644
--- a/src/vs/workbench/services/positronDataExplorer/common/positronDataExplorerDuckDBBackend.ts
+++ b/src/vs/workbench/services/positronDataExplorer/common/positronDataExplorerDuckDBBackend.ts
@@ -97,7 +97,7 @@ export class PositronDataExplorerDuckDBBackend extends Disposable implements IDa
 		private readonly uri: URI
 	) {
 		super();
-		this.clientId = `duckdb:${this.uri.path}`;
+		this.clientId = `duckdb:${this.uri.toString()}`;
 		this.initialSetup = this.openDataset();
 	}
 
diff --git a/src/vs/workbench/services/positronDataExplorer/common/positronDataExplorerUri.ts b/src/vs/workbench/services/positronDataExplorer/common/positronDataExplorerUri.ts
index 7da015f048a..ce8600aec39 100644
--- a/src/vs/workbench/services/positronDataExplorer/common/positronDataExplorerUri.ts
+++ b/src/vs/workbench/services/positronDataExplorer/common/positronDataExplorerUri.ts
@@ -56,4 +56,19 @@ export class PositronDataExplorerUri {
 			return undefined;
 		}
 	}
+
+	/**
+	 * Parses a Positron data explorer URI and retrieves the URI of the backing file, if any.
+	 * @param resource The data explorer resource.
+	 * @returns A URI for the backing file, if any.
+	 */
+	public static backingUri(resource: URI): URI | undefined {
+		const identifier = PositronDataExplorerUri.parse(resource);
+		// Runtime comm IDs have no originating URIs.
+		if (!identifier || !identifier.startsWith('duckdb:')) {
+			return undefined;
+		}
+		// This will be something like "duckdb:file:///path/to/file.csv".
+		return URI.parse(identifier.replace('duckdb:', ''));
+	}
 }