diff --git a/src/mdbx.c b/src/mdbx.c
index 4382be23..5182c2bf 100644
--- a/src/mdbx.c
+++ b/src/mdbx.c
@@ -3849,8 +3849,10 @@ static int mdbx_sync_locked(MDBX_env *env, unsigned flags,
     target = mdbx_meta_ancient(env, meta1, meta2, true);
   else if (head == meta1)
     target = mdbx_meta_ancient(env, meta0, meta2, true);
-  else if (head == meta2)
+  else {
+    mdbx_assert(env, head == meta2);
     target = mdbx_meta_ancient(env, meta0, meta1, true);
+  }
 
   /* LY: step#2 - update meta-page. */
   mdbx_debug(
@@ -6190,6 +6192,7 @@ static int mdbx_cursor_first(MDBX_cursor *mc, MDBX_val *key, MDBX_val *data) {
 
   if (likely(data)) {
     if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+      mdbx_cassert(mc, mc->mc_xcursor != nullptr);
       mdbx_xcursor_init1(mc, leaf);
       rc = mdbx_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
       if (unlikely(rc))
@@ -6233,6 +6236,7 @@ static int mdbx_cursor_last(MDBX_cursor *mc, MDBX_val *key, MDBX_val *data) {
 
   if (likely(data)) {
     if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+      mdbx_cassert(mc, mc->mc_xcursor != nullptr);
       mdbx_xcursor_init1(mc, leaf);
       rc = mdbx_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
       if (unlikely(rc))
diff --git a/src/osal.c b/src/osal.c
index 08ae9fef..ae28d191 100644
--- a/src/osal.c
+++ b/src/osal.c
@@ -549,7 +549,7 @@ int mdbx_write(mdbx_filehandle_t fd, const void *buf, size_t bytes) {
   sigset_t set, old;
   sigemptyset(&set);
   sigaddset(&set, SIGPIPE);
-  int rc = rc = pthread_sigmask(SIG_BLOCK, &set, &old);
+  int rc = pthread_sigmask(SIG_BLOCK, &set, &old);
   if (rc != 0)
     return rc;
 #endif