diff --git a/src/nvim/normal.c b/src/nvim/normal.c
index ba9dc88014..3f6443de66 100644
--- a/src/nvim/normal.c
+++ b/src/nvim/normal.c
@@ -106,6 +106,9 @@ static int VIsual_mode_orig = NUL;              // saved Visual mode
 # include "normal.c.generated.h"
 #endif
 
+static const char e_cmdline_window_already_open[]
+  = N_("E1292: Command-line window is already open");
+
 static inline void normal_state_init(NormalState *s)
 {
   memset(s, 0, sizeof(NormalState));
@@ -6384,6 +6387,10 @@ static void nv_record(cmdarg_T *cap)
   }
 
   if (cap->nchar == ':' || cap->nchar == '/' || cap->nchar == '?') {
+    if (cmdwin_type != 0) {
+      emsg(_(e_cmdline_window_already_open));
+      return;
+    }
     stuffcharReadbuff(cap->nchar);
     stuffcharReadbuff(K_CMDWIN);
   } else {
diff --git a/test/old/testdir/test_cmdwin.vim b/test/old/testdir/test_cmdwin.vim
new file mode 100644
index 0000000000..ef334c774f
--- /dev/null
+++ b/test/old/testdir/test_cmdwin.vim
@@ -0,0 +1,17 @@
+" Tests for editing the command line.
+
+source check.vim
+source screendump.vim
+
+
+func Test_cant_open_cmdwin_in_cmdwin()
+  try
+    call feedkeys("q:q::q\<CR>", "x!")
+  catch
+    let caught = v:exception
+  endtry
+  call assert_match('E1292:', caught)
+endfunc
+
+
+" vim: shiftwidth=2 sts=2 expandtab