diff --git a/src/vs/workbench/api/common/extHostTerminalShellIntegration.ts b/src/vs/workbench/api/common/extHostTerminalShellIntegration.ts
index cc5fccb9a8df8..1f8879fb7b575 100644
--- a/src/vs/workbench/api/common/extHostTerminalShellIntegration.ts
+++ b/src/vs/workbench/api/common/extHostTerminalShellIntegration.ts
@@ -184,7 +184,13 @@ class InternalTerminalShellIntegration extends Disposable {
 				return that._cwd;
 			},
 			get env(): vscode.TerminalShellIntegrationEnvironment | undefined {
-				return that._env;
+				if (!that._env) {
+					return undefined;
+				}
+				return Object.freeze({
+					isTrusted: that._env.isTrusted,
+					value: Object.freeze({ ...that._env.value })
+				});
 			},
 			get hasRichCommandDetection(): boolean {
 				return that._hasRichCommandDetection;