diff --git a/lib/processors/minifier.js b/lib/processors/minifier.js
index 76b2564b2..fc0b022d1 100644
--- a/lib/processors/minifier.js
+++ b/lib/processors/minifier.js
@@ -28,14 +28,20 @@ function getPool(taskUtil) {
 			workerType: "auto",
 			maxWorkers
 		});
-		taskUtil.registerCleanupTask(() => {
+		taskUtil.registerCleanupTask((options) => {
 			const attemptPoolTermination = () => {
 				log.verbose(`Attempt to terminate the workerpool...`);
 
+				if (!pool) {
+					return;
+				}
+
+				const forceTerminate = !!options && !!options.exitCode;
+
 				// There are many stats that could be used, but these ones seem the most
 				// convenient. When all the (available) workers are idle, then it's safe to terminate.
 				const {idleWorkers, totalWorkers} = pool.stats();
-				if (idleWorkers !== totalWorkers) {
+				if (idleWorkers !== totalWorkers && !forceTerminate) {
 					return new Promise((resolve) =>
 						setTimeout(() => resolve(attemptPoolTermination()), 100) // Retry after a while
 					);
@@ -43,7 +49,7 @@ function getPool(taskUtil) {
 
 				const poolToBeTerminated = pool;
 				pool = null;
-				return poolToBeTerminated.terminate();
+				return poolToBeTerminated.terminate(forceTerminate);
 			};
 
 			return attemptPoolTermination();
diff --git a/lib/tasks/buildThemes.js b/lib/tasks/buildThemes.js
index f3c1b263a..ce410d40b 100644
--- a/lib/tasks/buildThemes.js
+++ b/lib/tasks/buildThemes.js
@@ -23,14 +23,20 @@ function getPool(taskUtil) {
 			workerType: "thread",
 			maxWorkers
 		});
-		taskUtil.registerCleanupTask(() => {
+		taskUtil.registerCleanupTask((options) => {
 			const attemptPoolTermination = () => {
 				log.verbose(`Attempt to terminate the workerpool...`);
 
+				if (!pool) {
+					return;
+				}
+
+				const forceTerminate = !!options && !!options.exitCode;
+
 				// There are many stats that could be used, but these ones seem the most
 				// convenient. When all the (available) workers are idle, then it's safe to terminate.
 				const {idleWorkers, totalWorkers} = pool.stats();
-				if (idleWorkers !== totalWorkers) {
+				if (idleWorkers !== totalWorkers && !forceTerminate) {
 					return new Promise((resolve) =>
 						setTimeout(() => resolve(attemptPoolTermination()), 100) // Retry after a while
 					);
@@ -38,7 +44,7 @@ function getPool(taskUtil) {
 
 				const poolToBeTerminated = pool;
 				pool = null;
-				return poolToBeTerminated.terminate();
+				return poolToBeTerminated.terminate(forceTerminate);
 			};
 
 			return attemptPoolTermination();