1 files changed, 1 insertions, 0 deletions
diff --git a/bin/pngo.c b/bin/pngo.c
index c34ec7d1..eada7e01 100644
--- a/bin/pngo.c
+++ b/bin/pngo.c
@@ -132,6 +132,7 @@ static struct PACKED {
     enum PACKED { ADAPTIVE } filter;
     enum PACKED { PROGRESSIVE, ADAM7 } interlace;
 } header;
+static_assert(13 == sizeof(header), "header size");
 
 static size_t lineSize(void) {
     switch (header.color) {