diff --git a/package.json b/package.json
index 3a17c5d2..d2558920 100644
--- a/package.json
+++ b/package.json
@@ -403,7 +403,7 @@
                 "description": "%java.debugger.attach.hostName.description%"
               },
               "port": {
-                "type": "number",
+                "type": ["number", "string"],
                 "description": "%java.debugger.attach.port.description%"
               },
               "processId": {
diff --git a/src/configurationProvider.ts b/src/configurationProvider.ts
index 17eb273e..4d96da32 100644
--- a/src/configurationProvider.ts
+++ b/src/configurationProvider.ts
@@ -313,7 +313,8 @@ export class JavaDebugConfigurationProvider implements vscode.DebugConfiguration
                     }
                 }
             } else if (config.request === "attach") {
-                if (config.hostName && config.port) {
+                if (config.hostName && config.port && Number.isInteger(Number(config.port))) {
+                    config.port = Number(config.port);
                     config.processId = undefined;
                     // Continue if the hostName and port are configured.
                 } else if (config.processId !== undefined) {