diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 26acc07..46f2b22 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -3435,7 +3435,7 @@
 
     STRCAT(IObuff, ": ");
     d = IObuff + STRLEN(IObuff);
-    while (*s != NUL && d - IObuff < IOSIZE - 7)
+    while (*s != NUL && d - IObuff + 5 < IOSIZE)
     {
 	if (enc_utf8 ? (s[0] == 0xc2 && s[1] == 0xa0) : *s == 0xa0)
 	{
@@ -3443,6 +3443,8 @@
 	    STRCPY(d, "<a0>");
 	    d += 4;
 	}
+	else if (d - IObuff + (*mb_ptr2len)(s) + 1 >= IOSIZE)
+	    break;
 	else
 	    MB_COPY_CHAR(s, d);
     }
diff --git a/src/testdir/test_cmdline.vim b/src/testdir/test_cmdline.vim
index 8d556fa..474638f 100644
--- a/src/testdir/test_cmdline.vim
+++ b/src/testdir/test_cmdline.vim
@@ -3353,6 +3353,17 @@
   set wildmenu&
 endfunc
 
+" this was going over the end of IObuff
+func Test_report_error_with_composing()
+  let caught = 'no'
+  try
+    exe repeat('0', 987) .. "0\xdd\x80\xdd\x80\xdd\x80\xdd\x80"
+  catch /E492:/
+    let caught = 'yes'
+  endtry
+  call assert_equal('yes', caught)
+endfunc
+
 " Test for expanding 2-letter and 3-letter :substitute command arguments.
 " These commands don't accept an argument.
 func Test_cmdline_complete_substitute_short()
diff --git a/src/version.c b/src/version.c
index 0857bcb..df30685 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4895,
+/**/
     4894,
 /**/
     4893,