diff --git a/tests/Makefile.am b/tests/Makefile.am
index 2787cac7..200faf7e 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -905,7 +905,7 @@ check_PROGRAMS += test_media_blocks
 test_media_blocks_SOURCES = test_media_blocks.c media_delivery_fixture.h
 test_media_blocks_CFLAGS = $(test_media_delivery_download_CFLAGS)
 test_media_blocks_LDADD = $(LIBUTUN) $(CRYPTO_LIBS) $(COMMON_LIBS)
-test_media_blocks_LDFLAGS = -Wl,--wrap=etcp_route_send -Wl,--wrap=RAND_bytes -Wl,--wrap=fwrite -Wl,--wrap=fread \
+test_media_blocks_LDFLAGS = -Wl,--wrap=etcp_route_send -Wl,--wrap=RAND_bytes -Wl,--wrap=fwrite -Wl,--wrap=fread -Wl,--wrap=__fread_chk \
     -Wl,--wrap=fseeko -Wl,--wrap=fclose -Wl,--wrap=fflush -Wl,--wrap=rename -Wl,--wrap=ma_sha256_file
 
 test_media_delivery_integration_SOURCES = test_media_delivery_integration.c
diff --git a/tests/test_media_blocks.c b/tests/test_media_blocks.c
index 5140569c..0c7f64e7 100644
--- a/tests/test_media_blocks.c
+++ b/tests/test_media_blocks.c
@@ -23,6 +23,11 @@ size_t __wrap_fread(void* bytes, size_t size, size_t count, FILE* file) {
     if (fail_io(IO_READ)) return 0;
     return __real_fread(bytes, size, count, file);
 }
+size_t __real___fread_chk(void*, size_t, size_t, size_t, FILE*);
+size_t __wrap___fread_chk(void* bytes, size_t capacity, size_t size, size_t count, FILE* file) {
+    if (fail_io(IO_READ)) return 0;
+    return __real___fread_chk(bytes, capacity, size, count, file);
+}
 int __real_fseeko(FILE*, off_t, int);
 int __wrap_fseeko(FILE* file, off_t offset, int origin) {
     return fail_io(IO_SEEK) ? -1 : __real_fseeko(file, offset, origin);
@@ -223,6 +228,9 @@ static void test_io_failures(void) {
             if (variant == 7) fault_skip = 2;
             receive(f.client, &done);
         }
+        if (fault_hits != 1 || download(f.client) || done_count != 1 || done_err != -1)
+            DEBUG_ERROR(DEBUG_CATEGORY_DEBUG, "IO regression variant=%d fault=%d hits=%d remaining_skip=%d active=%p done=%d error=%d",
+                        variant, fault, fault_hits, fault_skip, (void*)download(f.client), done_count, done_err);
         REQUIRE(fault_hits == 1 && !download(f.client) && done_count == 1 && done_err == -1);
         REQUIRE(!f.client->md.destinations && !f.client->md.block_sources->head);
         require_old_destination(); finish(&f);
diff --git a/tests/test_media_delivery_sql.c b/tests/test_media_delivery_sql.c
index 0bb75b1b..13cbe212 100644
--- a/tests/test_media_delivery_sql.c
+++ b/tests/test_media_delivery_sql.c
@@ -401,8 +401,11 @@ static void test_proto_sizes(void) {
         if (sizeof(struct media_pkt_super_hello) != 17)  { FAIL("super_hello: %zu != 17", sizeof(struct media_pkt_super_hello)); ok = 0; }
         if (sizeof(struct media_pkt_super_ack) != 5)   { FAIL("super_ack: %zu != 5", sizeof(struct media_pkt_super_ack)); ok = 0; }
         if (sizeof(struct media_pkt_block_req) != 53)   { FAIL("block_req: %zu != 53", sizeof(struct media_pkt_block_req)); ok = 0; }
-        if (sizeof(struct media_pkt_cancel) != 37)      { FAIL("cancel: %zu != 37", sizeof(struct media_pkt_cancel)); ok = 0; }
-        if (sizeof(struct media_pkt_block_done) != 105) { FAIL("block_done: %zu != 105", sizeof(struct media_pkt_block_done)); ok = 0; }
+        if (sizeof(struct media_pkt_cancel) != 53)      { FAIL("cancel: %zu != 53", sizeof(struct media_pkt_cancel)); ok = 0; }
+        if (sizeof(struct media_pkt_block_done) != 58) { FAIL("block_done: %zu != 58", sizeof(struct media_pkt_block_done)); ok = 0; }
+        if (sizeof(struct media_pkt_block_chunk) != 59) { FAIL("block_chunk: %zu != 59", sizeof(struct media_pkt_block_chunk)); ok = 0; }
+        if (sizeof(struct media_pkt_block_overloaded) != 57) { FAIL("overloaded: %zu != 57", sizeof(struct media_pkt_block_overloaded)); ok = 0; }
+        if (sizeof(struct media_pkt_block_relay_full) != 55) { FAIL("relay_full: %zu != 55", sizeof(struct media_pkt_block_relay_full)); ok = 0; }
         if (sizeof(struct media_pkt_query_resp_entry) != 49) { FAIL("query_resp_entry: %zu != 49", sizeof(struct media_pkt_query_resp_entry)); ok = 0; }
         if (sizeof(struct media_pkt_query_resp) != 36) { FAIL("query_resp: %zu != 36", sizeof(struct media_pkt_query_resp)); ok = 0; }
         if (ok) OK();