diff --git a/src/encoders/omx/encoder.c b/src/encoders/omx/encoder.c
index 7485519..db114d1 100644
--- a/src/encoders/omx/encoder.c
+++ b/src/encoders/omx/encoder.c
@@ -305,9 +305,7 @@ static int _omx_setup_input(struct omx_encoder_t *omx, struct device_t *dev) {
 	portdef.format.image.nFrameWidth = dev->run->width;
 	portdef.format.image.nFrameHeight = dev->run->height;
 	portdef.format.image.nStride = 0;
-#	define ALIGN_HEIGHT(_x, _y) (((_x) + ((_y) - 1)) & ~((_y) - 1))
-	portdef.format.image.nSliceHeight = ALIGN_HEIGHT(dev->run->height, 16);
-#	undef ALIGN_HEIGHT
+	portdef.format.image.nSliceHeight = align_size(dev->run->height, 16);
 	portdef.format.image.bFlagErrorConcealment = OMX_FALSE;
 	portdef.format.image.eCompressionFormat = OMX_IMAGE_CodingUnused;
 	portdef.nBufferSize = picture_get_generous_size(dev->run->width, dev->run->height);
diff --git a/src/tools.h b/src/tools.h
index 80e64c5..a41c879 100644
--- a/src/tools.h
+++ b/src/tools.h
@@ -45,6 +45,10 @@ INLINE char *bool_to_string(bool flag) {
 	return (flag ? "true" : "false");
 }
 
+INLINE size_t align_size(size_t size, size_t to) {
+	return ((size + (to - 1)) & ~(to - 1));
+}
+
 INLINE unsigned min_u(unsigned a, unsigned b) {
 	return (a < b ? a : b);
 }