diff --git a/arduino-debugger-extension/src/browser/arduino-debug-session-manager.ts b/arduino-debugger-extension/src/browser/arduino-debug-session-manager.ts
new file mode 100644
index 00000000..79f81d58
--- /dev/null
+++ b/arduino-debugger-extension/src/browser/arduino-debug-session-manager.ts
@@ -0,0 +1,14 @@
+import { DebugSessionManager } from "@theia/debug/lib/browser/debug-session-manager";
+import { DebugSessionOptions } from "@theia/debug/lib/browser/debug-session-options";
+
+export class ArduinoDebugSessionManager extends DebugSessionManager {
+
+    start(options: DebugSessionOptions) {
+        if (options.configuration.type === 'arduino' && this.sessions.find(s => s.configuration.type === 'arduino')) {
+            this.messageService.info('A debug session is already running. You must stop the running session before starting a new one.')
+            return Promise.resolve(undefined);
+        }
+        return super.start(options);
+    }
+
+}
diff --git a/arduino-debugger-extension/src/browser/frontend-module.ts b/arduino-debugger-extension/src/browser/frontend-module.ts
index f3223dba..d02ff16e 100644
--- a/arduino-debugger-extension/src/browser/frontend-module.ts
+++ b/arduino-debugger-extension/src/browser/frontend-module.ts
@@ -1,14 +1,17 @@
 import { ContainerModule } from 'inversify';
 import { VariableContribution } from '@theia/variable-resolver/lib/browser';
 import { ArduinoVariableResolver } from './arduino-variable-resolver';
+import { DebugSessionManager } from '@theia/debug/lib/browser/debug-session-manager';
 import { DebugFrontendApplicationContribution } from '@theia/debug/lib/browser/debug-frontend-application-contribution';
 import { DebugConfigurationManager } from '@theia/debug/lib/browser/debug-configuration-manager';
 import { ArduinoDebugConfigurationManager } from './arduino-debug-configuration-manager';
 import { ArduinoDebugFrontendApplicationContribution } from './arduino-debug-frontend-application-contribution';
+import { ArduinoDebugSessionManager } from './arduino-debug-session-manager';
 
 export default new ContainerModule((bind, unbind, isBound, rebind) => {
     bind(ArduinoVariableResolver).toSelf().inSingletonScope();
     bind(VariableContribution).toService(ArduinoVariableResolver);
+    rebind(DebugSessionManager).to(ArduinoDebugSessionManager).inSingletonScope();
     rebind(DebugConfigurationManager).to(ArduinoDebugConfigurationManager).inSingletonScope();
     rebind(DebugFrontendApplicationContribution).to(ArduinoDebugFrontendApplicationContribution);
 });