diff --git a/src/vim9compile.c b/src/vim9compile.c
index 663a52d..404c819 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -7711,6 +7711,7 @@
     int		semicolon = FALSE;
     size_t	varlen;
     garray_T	*stack = &cctx->ctx_type_stack;
+    garray_T	*instr = &cctx->ctx_instr;
     scope_T	*scope;
     lvar_T	*loop_lvar;	// loop iteration variable
     lvar_T	*var_lvar;	// variable for "var"
@@ -7737,6 +7738,13 @@
     if (may_get_next_line_error(wp, &p, cctx) == FAIL)
 	return NULL;
 
+    // Remove the already generated ISN_DEBUG, it is written below the ISN_FOR
+    // instruction.
+    if (cctx->ctx_compile_type == CT_DEBUG && instr->ga_len > 0
+	    && ((isn_T *)instr->ga_data)[instr->ga_len - 1]
+							.isn_type == ISN_DEBUG)
+	--instr->ga_len;
+
     scope = new_scope(cctx, FOR_SCOPE);
     if (scope == NULL)
 	return NULL;
@@ -7788,11 +7796,12 @@
 	    item_type = vartype->tt_member->tt_member;
     }
 
-    // CMDMOD_REV must come before the FOR instruction
+    // CMDMOD_REV must come before the FOR instruction.
     generate_undo_cmdmods(cctx);
 
     // "for_end" is set when ":endfor" is found
     scope->se_u.se_for.fs_top_label = current_instr_idx(cctx);
+
     generate_FOR(cctx, loop_lvar->lv_idx);
 
     arg = arg_start;
@@ -7893,6 +7902,10 @@
 	vim_free(name);
     }
 
+    if (cctx->ctx_compile_type == CT_DEBUG)
+	// Add ISN_DEBUG here, so that the loop variables can be inspected.
+	generate_instr_debug(cctx);
+
     return arg_end;
 
 failed:
@@ -7927,7 +7940,7 @@
     // At end of ":for" scope jump back to the FOR instruction.
     generate_JUMP(cctx, JUMP_ALWAYS, forscope->fs_top_label);
 
-    // Fill in the "end" label in the FOR statement so it can jump here
+    // Fill in the "end" label in the FOR statement so it can jump here.
     isn = ((isn_T *)instr->ga_data) + forscope->fs_top_label;
     isn->isn_arg.forloop.for_end = instr->ga_len;
 
@@ -8234,6 +8247,7 @@
 #ifdef FEAT_PROFILE
 	// the profile-start should be after the jump
 	if (cctx->ctx_compile_type == CT_PROFILE
+		&& instr->ga_len > 0
 		&& ((isn_T *)instr->ga_data)[instr->ga_len - 1]
 						   .isn_type == ISN_PROF_START)
 	    --instr->ga_len;