diff --git a/src/vs/vscode.d.ts b/src/vs/vscode.d.ts
index 6d97b13d0ae16c55bb2adb65fb077e8840065fd4..7c5c6828b6a79e39bdc2c4b46851f347d0d93f2f 100644
--- a/src/vs/vscode.d.ts
+++ b/src/vs/vscode.d.ts
@@ -9273,7 +9273,7 @@ declare module 'vscode' {
 		 * Implement to handle when the number of rows and columns that fit into the terminal panel
 		 * changes, for example when font size changes or when the panel is resized. The initial
 		 * state of a terminal's dimensions should be treated as `undefined` until this is triggered
-		 * as the size of a terminal isn't know until it shows up in the user interface.
+		 * as the size of a terminal isn't known until it shows up in the user interface.
 		 *
 		 * When dimensions are overridden by
 		 * [onDidOverrideDimensions](#Pseudoterminal.onDidOverrideDimensions), `setDimensions` will
diff --git a/src/vs/workbench/api/common/extHostTerminalService.ts b/src/vs/workbench/api/common/extHostTerminalService.ts
index 5f6034363c2f76caf3317075fd2e2d156ebe3331..f684dbb85b4b993e9d0e656f1f318a3961158b1c 100644
--- a/src/vs/workbench/api/common/extHostTerminalService.ts
+++ b/src/vs/workbench/api/common/extHostTerminalService.ts
@@ -250,6 +250,11 @@ export class ExtHostPseudoterminal implements ITerminalChildProcess {
 		}
 
 		this._pty.open(initialDimensions ? initialDimensions : undefined);
+
+		if (this._pty.setDimensions && initialDimensions) {
+			this._pty.setDimensions(initialDimensions);
+		}
+
 		this._onProcessReady.fire({ pid: -1, cwd: '' });
 	}
 }