diff --git a/source/compiler/sc1.c b/source/compiler/sc1.c
index 9603610..ae00669 100644
--- a/source/compiler/sc1.c
+++ b/source/compiler/sc1.c
@@ -3246,8 +3246,6 @@ static int getstates(const char *funcname)
 static void attachstatelist(symbol *sym, int state_id)
 {
   assert(sym!=NULL);
-  if ((sym->usage & uDEFINE)!=0 && (sym->states==NULL || state_id==0))
-    error(21,sym->name); /* function already defined, either without states or the current definition has no states */
 
   if (state_id!=0) {
     /* add the state list id */
@@ -3947,7 +3945,6 @@ static int newfunc(char *firstname,int firsttag,int fpublic,int fstatic,int stoc
   state_id=getstates(symbolname);
   if (state_id>0 && (opertok!=0 || strcmp(symbolname,uMAINFUNC)==0))
     error(82);          /* operators may not have states, main() may neither */
-  attachstatelist(sym,state_id);
   pc_deprecate=bck_deprecate;
   pc_attributes=bck_attributes;
   if (matchtoken(t__PRAGMA))
@@ -3959,9 +3956,12 @@ static int newfunc(char *firstname,int firsttag,int fpublic,int fstatic,int stoc
     sym->usage|=uFORWARD;
     if (!sc_needsemicolon)
       error(218);       /* old style prototypes used with optional semicolons */
+    if (state_id!=0)
+      error(231);       /* state specification on forward declaration is ignored */
     delete_symbols(&loctab,0,TRUE,TRUE);  /* prototype is done; forget everything */
     return TRUE;
   } /* if */
+  attachstatelist(sym,state_id);
   /* so it is not a prototype, proceed */
   /* if this is a function that is not referred to (this can only be detected
    * in the second stage), shut code generation off */
@@ -3970,6 +3970,8 @@ static int newfunc(char *firstname,int firsttag,int fpublic,int fstatic,int stoc
     cidx=code_idx;
     glbdecl=glb_declared;
   } /* if */
+  if ((sym->usage & uDEFINE)!=0 && (sym->states==NULL || state_id==0))
+    error(21,sym->name); /* function already defined, either without states or the current definition has no states */
   if ((sym->flags & flagDEPRECATED)!=0 && fpublic) {
     char *ptr= (sym->documentation!=NULL) ? sym->documentation : "";
     error(234,symbolname,ptr);  /* deprecated (definitely a public function) */
diff --git a/source/compiler/tests/warning_231.meta b/source/compiler/tests/warning_231.meta
new file mode 100644
index 0000000..1e107c3
--- /dev/null
+++ b/source/compiler/tests/warning_231.meta
@@ -0,0 +1,7 @@
+{
+  'test_type': 'output_check',
+  'errors': """
+warning_231.pwn(3) : warning 231: state specification on forward declaration is ignored
+warning_231.pwn(6) : warning 231: state specification on forward declaration is ignored
+"""
+}
diff --git a/source/compiler/tests/warning_231.pwn b/source/compiler/tests/warning_231.pwn
new file mode 100644
index 0000000..1df19a1
--- /dev/null
+++ b/source/compiler/tests/warning_231.pwn
@@ -0,0 +1,9 @@
+#pragma option -;+
+
+forward Func() <auto1:st1>; // warning 231: state specification on forward declaration is ignored
+public Func() <auto1:st1> {}
+
+public Func() <auto1:st2>; // warning 231: state specification on forward declaration is ignored
+public Func() <auto1:st2> {}
+
+main(){}