diff --git a/src/testdir/test_debugger.vim b/src/testdir/test_debugger.vim
index a6e3966..411909d 100644
--- a/src/testdir/test_debugger.vim
+++ b/src/testdir/test_debugger.vim
@@ -958,6 +958,10 @@
          a: 1,
          b: 2,
          }
+         # comment
+         def Inner()
+           eval 1
+         enddef
     enddef
   END
   call writefile(file, 'Xtest.vim')
@@ -997,6 +1001,7 @@
                 \ ':debug call FuncWithDict()',
                 \ ['cmd: call FuncWithDict()'])
   call RunDbgCmd(buf, 'step', ['line 1: var d = {  a: 1,  b: 2,  }'])
+  call RunDbgCmd(buf, 'step', ['line 6: def Inner()'])
 
   call RunDbgCmd(buf, 'cont')
   call StopVimInTerminal(buf)
diff --git a/src/version.c b/src/version.c
index a03b3fe..69aa0e7 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3017,
+/**/
     3016,
 /**/
     3015,
diff --git a/src/vim9execute.c b/src/vim9execute.c
index 2577e63..218357a 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -1461,9 +1461,17 @@
     {
 	ga_init2(&ga, sizeof(char_u *), 10);
 	for (lnum = iptr->isn_lnum; lnum < end_lnum; ++lnum)
+	{
+	    char_u *p = skipwhite(
+			       ((char_u **)ufunc->uf_lines.ga_data)[lnum - 1]);
+
+	    if (*p == '#')
+		break;
 	    if (ga_grow(&ga, 1) == OK)
-		((char_u **)(ga.ga_data))[ga.ga_len++] =
-		     skipwhite(((char_u **)ufunc->uf_lines.ga_data)[lnum - 1]);
+		((char_u **)(ga.ga_data))[ga.ga_len++] = p;
+	    if (STRNCMP(p, "def ", 4) == 0)
+		break;
+	}
 	line = ga_concat_strings(&ga, "  ");
 	vim_free(ga.ga_data);
     }