diff --git a/.gitignore b/.gitignore
index 634a205..dcb7563 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 *.o
 *.a
+.d
 gwfmt
diff --git a/include/gwfmt.h b/include/gwfmt.h
index c4516af..66ea45d 100644
--- a/include/gwfmt.h
+++ b/include/gwfmt.h
@@ -68,7 +68,8 @@ typedef struct GwfmtState {
   bool         header;
   bool         use_tabs;
   bool         error;
-  bool         fix;
+  bool         fix_case;
+  bool         check_case;
 } GwfmtState;
 
 void gwfmt_state_init(GwfmtState *ls);
diff --git a/src/gwfmt.c b/src/gwfmt.c
index 7e66882..fadb4c0 100644
--- a/src/gwfmt.c
+++ b/src/gwfmt.c
@@ -84,7 +84,8 @@ enum {
 //  MARK,
   EXPAND,
   MINIFY,
-  CASING,
+  FIX_CASING,
+  CHECK_CASING,
   CONFIG,
   COLOR,
   NOPTIONS
@@ -110,7 +111,9 @@ static void setup_options(cmdapp_t *app, cmdopt_t *opt) {
   cmdapp_set(app, 'm', "minify", CMDOPT_TAKESARG, NULL, "minimize input",
              "bool", &opt[MINIFY]);
   cmdapp_set(app, 'f', "fix", CMDOPT_TAKESARG, NULL, "fix casing",
-             "bool", &opt[CASING]);
+             "bool", &opt[FIX_CASING]);
+  cmdapp_set(app, 'w', "fix", CMDOPT_TAKESARG, NULL, "check casing",
+             "bool", &opt[CHECK_CASING]);
   cmdapp_set(app, 'C', "config", CMDOPT_TAKESARG, NULL, "config file",
              "filename", &opt[CONFIG]);
   cmdapp_set(app, 'c', "color", CMDOPT_TAKESARG, NULL, "enable or disable {R}c{G}o{B}l{M}o{Y}r{C}s{0}",
@@ -179,7 +182,10 @@ static void myproc(void *data, cmdopt_t *option, const char *arg) {
         ls->minimize = arg2bool(option->value);
         break;
       case 'f':
-        ls->fix = arg2bool(option->value);
+        ls->fix_case = arg2bool(option->value);
+        break;
+      case 'w':
+        ls->check_case = arg2bool(option->value);
         break;
       case 'C':
         run_config(ls, option->value);
@@ -221,7 +227,14 @@ int main(int argc, char **argv) {
   SymTable *    st  = new_symbol_table(mp, 65347); // could be smaller
   PPArg ppa = {.fmt = 1};
   pparg_ini(mp, &ppa);
-  struct GwfmtState ls = {.color = isatty(1) ? COLOR_AUTO : COLOR_NEVER, .show_line = true, .header = true, .nindent = 2, .ppa = &ppa, .minimize = false };
+  struct GwfmtState ls = {
+    .color = isatty(1) ? COLOR_AUTO : COLOR_NEVER,
+    .show_line = true,
+    .header = true,
+    .nindent = 2,
+    .ppa = &ppa,
+    .minimize = false,
+    .check_case = true};
   tcol_override_color_checks(ls.color);
   gwfmt_state_init(&ls);
   text_init(&ls.text, mp);
diff --git a/src/gwion_config.c b/src/gwion_config.c
index 76ae043..4b9e2d5 100644
--- a/src/gwion_config.c
+++ b/src/gwion_config.c
@@ -24,7 +24,8 @@ runtime_bool_func(pretty, pretty);
 runtime_bool_func(show_lines, show_line);
 runtime_bool_func(header, header);
 runtime_bool_func(use_tabs, use_tabs);
-runtime_bool_func(fix, fix);
+runtime_bool_func(fix_case, fix_case);
+runtime_bool_func(check_case, check_case);
 
 static MFUN(fmt_color) {
   struct GwfmtState *ls = **(struct GwfmtState***)MEM(0);
@@ -93,7 +94,8 @@ GWION_IMPORT(GwFmt) {
  import_bool_fun(header); 
  import_bool_fun(show_lines); 
  import_bool_fun(use_tabs); 
- import_bool_fun(fix); 
+ import_bool_fun(fix_case); 
+ import_bool_fun(check_case); 
 
   GWI_B(gwi_func_ini(gwi, "void", "color"));
     GWI_B(gwi_func_arg(gwi, "ColorWhen", "arg"));
diff --git a/src/lint.c b/src/lint.c
index 3dbc5ae..04daf58 100644
--- a/src/lint.c
+++ b/src/lint.c
@@ -68,14 +68,15 @@ void flow(Gwfmt *a, const char *kw) {
 ANN static void check_tag(Gwfmt *a, const Tag * tag, const CaseType ct,
                           char* color) {
   const Casing casing = a->ls->config->cases[ct];
-  if(!casing.check(s_name(tag->sym))) {
+  if(a->ls->check_case && !casing.check(s_name(tag->sym))) {
    a->ls->error = true;
-   if(!a->ls->fix) {
+   if(!a->ls->fix_case) {
       char main[256];
       char info[256];
       snprintf(main, sizeof(main) - 1, "invalid {Y+}%s{0} casing", ct_name[ct]);
       snprintf(info, sizeof(info) - 1, "should be {W+}%s{0} case", casing.name);
-      gwlog_error(main, info, a->filename, tag->loc, 0);
+      printf("filename: %s\n", a->filename);
+      gwlog_error(main, info, a->filename ?: "/dev/null", tag->loc, 0);
     } else {
       char buf[256];
       const char *name = s_name(tag->sym);