diff --git a/hi/bs.h b/hi/bs.h
index f580a00..5214aa9 100644
--- a/hi/bs.h
+++ b/hi/bs.h
@@ -85,6 +85,7 @@ static inline CHiBSFrames *CHi_BS_Grow(CHiBSFrames *bsfs, size_t num) {
 	size_t oldsz = sizeof(*bsfs) + sizeof(CHiBSFrame) * bsfs->count;
 	size_t newsz = sizeof(*bsfs) + sizeof(CHiBSFrame) * (bsfs->count + num);
 	CHiBSFrames *ret = (CHiBSFrames*) realloc(bsfs, newsz);
+	ret->count += num;
 	memset((uint8_t*) ret + oldsz, 0, newsz - oldsz);
 	return ret;
 }
diff --git a/hi/img.c b/hi/img.c
index 3777f10..b559178 100644
--- a/hi/img.c
+++ b/hi/img.c
@@ -2,6 +2,7 @@
 
 #include<mm_malloc.h>
 #include<string.h>
+#include<assert.h>
 
 CUTIVIS CHiImage* CHi_Image_New(uint8_t bpc, uint8_t channels, uint16_t stride, uint16_t width, uint16_t height, void *data) {
 	CHiImage *img = malloc(sizeof(*img));
@@ -14,6 +15,8 @@ CUTIVIS CHiImage* CHi_Image_New(uint8_t bpc, uint8_t channels, uint16_t stride,
 	else img->data16 = _mm_malloc(bpc * stride * height, 16);
 	img->owned = !data;
 	
+	assert(stride % 16 == 0);
+	
 	return img;
 }