1 files changed, 5 insertions, 0 deletions
diff --git a/src/nvim/regexp_bt.c b/src/nvim/regexp_bt.c
index f0efd06cc0..6f63b38a90 100644
--- a/src/nvim/regexp_bt.c
+++ b/src/nvim/regexp_bt.c
@@ -1971,6 +1971,11 @@ static char_u *regatom(int *flagp)
       break;
 
     case '#':
+      if (regparse[0] == '=' && regparse[1] >= 48 && regparse[1] <= 50) {
+        // misplaced \%#=1
+        semsg(_(e_atom_engine_must_be_at_start_of_pattern), regparse[1]);
+        return FAIL;
+      }
       ret = regnode(CURSOR);
       break;