diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
index 00559ce318e1..af51fb2d1718 100644
--- a/src/libcamera/pipeline/ipu3/ipu3.cpp
+++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
@@ -185,7 +185,7 @@ void IPU3CameraConfiguration::adjustStream(StreamConfiguration &cfg, bool scale)
 		 * Provide a suitable default that matches the sensor aspect
 		 * ratio.
 		 */
-		if (!cfg.size.width || !cfg.size.height) {
+		if (cfg.size.isNull()) {
 			cfg.size.width = 1280;
 			cfg.size.height = 1280 * cio2Configuration_.size.height
 					/ cio2Configuration_.size.width;
diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
index 3c3f3f3a8049..051d77a68b55 100644
--- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
+++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
@@ -506,7 +506,7 @@ CameraConfiguration::Status RkISP1CameraConfiguration::validate()
 					    MEDIA_BUS_FMT_SGRBG8_1X8,
 					    MEDIA_BUS_FMT_SRGGB8_1X8 },
 					  cfg.size);
-	if (!sensorFormat_.size.width || !sensorFormat_.size.height)
+	if (sensorFormat_.size.isNull())
 		sensorFormat_.size = sensor->resolution();
 
 	/*
@@ -517,7 +517,7 @@ CameraConfiguration::Status RkISP1CameraConfiguration::validate()
 	 */
 	const Size size = cfg.size;
 
-	if (!cfg.size.width || !cfg.size.height) {
+	if (cfg.size.isNull()) {
 		cfg.size.width = 1280;
 		cfg.size.height = 1280 * sensorFormat_.size.height
 				/ sensorFormat_.size.width;
diff --git a/test/v4l2_subdevice/test_formats.cpp b/test/v4l2_subdevice/test_formats.cpp
index 9635c9948946..679f50b62c4d 100644
--- a/test/v4l2_subdevice/test_formats.cpp
+++ b/test/v4l2_subdevice/test_formats.cpp
@@ -67,7 +67,7 @@ int FormatHandlingTest::run()
 		return TestFail;
 	}
 
-	if (format.size.width == 0 || format.size.height == 0) {
+	if (format.size.isNull()) {
 		cerr << "Failed to update image format" << endl;
 		return TestFail;
 	}