diff --git a/source/compiler/sc1.c b/source/compiler/sc1.c
index 43c5a7b..53b0154 100644
--- a/source/compiler/sc1.c
+++ b/source/compiler/sc1.c
@@ -5370,9 +5370,10 @@ static void destructsymbols(symbol *root,int level)
       if ((opsym=findglb(symbolname,sGLOBAL))!=NULL) {
         if ((opsym->usage & uMISSING)!=0 || (opsym->usage & uPROTOTYPED)==0) {
           char symname[2*sNAMEMAX+16];  /* allow space for user defined operators */
+          char *ptr= (sym->documentation!=NULL) ? sym->documentation : "";
           funcdisplayname(symname,opsym->name);
           if ((opsym->usage & uMISSING)!=0)
-            error(4,symname);           /* function not defined */
+            error(4,symname,ptr);       /* function not defined */
           if ((opsym->usage & uPROTOTYPED)==0)
             error(71,symname);          /* operator must be declared before use */
         } /* if */
diff --git a/source/compiler/sc3.c b/source/compiler/sc3.c
index 886d22d..b549c33 100644
--- a/source/compiler/sc3.c
+++ b/source/compiler/sc3.c
@@ -200,9 +200,10 @@ static void (*unopers[])(void) = { lneg, neg, user_inc, user_dec };
   /* check existence and the proper declaration of this function */
   if ((sym->usage & uMISSING)!=0 || (sym->usage & uPROTOTYPED)==0) {
     char symname[2*sNAMEMAX+16];  /* allow space for user defined operators */
+    char *ptr= (sym->documentation!=NULL) ? sym->documentation : "";
     funcdisplayname(symname,sym->name);
     if ((sym->usage & uMISSING)!=0)
-      error(4,symname);           /* function not defined */
+      error(4,symname,ptr);       /* function not defined */
     if ((sym->usage & uPROTOTYPED)==0)
       error(71,symname);          /* operator must be declared before use */
   } /* if */
@@ -1979,8 +1980,9 @@ restart:
         } /* if */
       } else if ((sym->usage & uMISSING)!=0) {
         char symname[2*sNAMEMAX+16];  /* allow space for user defined operators */
+        char *ptr= (sym->documentation!=NULL) ? sym->documentation : "";
         funcdisplayname(symname,sym->name);
-        error(4,symname);             /* function not defined */
+        error(4,symname,ptr);         /* function not defined */
       } /* if */
       callfunction(sym,lval1,TRUE);
       return FALSE;             /* result of function call is no lvalue */
diff --git a/source/compiler/sc5.c b/source/compiler/sc5.c
index fc2eb8d..384e8e2 100644
--- a/source/compiler/sc5.c
+++ b/source/compiler/sc5.c
@@ -43,7 +43,7 @@ static char *errmsg[] = {
 /*001*/  "expected token: \"%s\", but found \"%s\"\n",
 /*002*/  "only a single statement (or expression) can follow each \"case\"\n",
 /*003*/  "declaration of a local variable must appear in a compound block\n",
-/*004*/  "function \"%s\" is not implemented\n",
+/*004*/  "function \"%s\" is not implemented %s\n",
 /*005*/  "function may not have arguments\n",
 /*006*/  "must be assigned to an array\n",
 /*007*/  "operator cannot be redefined\n",
diff --git a/source/compiler/tests/gh_500.meta b/source/compiler/tests/gh_500.meta
new file mode 100644
index 0000000..0ebab4f
--- /dev/null
+++ b/source/compiler/tests/gh_500.meta
@@ -0,0 +1,8 @@
+{
+  'test_type': 'output_check',
+  'errors': """
+gh_500.pwn(13) : error 004: function "Test1" is not implemented - use "Test4"
+gh_500.pwn(14) : error 004: function "Test2" is not implemented 
+gh_500.pwn(15) : error 004: function "Test3" is not implemented 
+"""
+}
diff --git a/source/compiler/tests/gh_500.pwn b/source/compiler/tests/gh_500.pwn
new file mode 100644
index 0000000..f3d0a87
--- /dev/null
+++ b/source/compiler/tests/gh_500.pwn
@@ -0,0 +1,16 @@
+#pragma deprecated - use "Test4"
+forward Test1();
+
+#pragma deprecated
+forward Test2();
+
+forward Test3();
+
+stock Test4(){}
+
+main()
+{
+	Test1(); // error 004: function "Test1" is not implemented - use "Test4"
+	Test2(); // error 004: function "Test2" is not implemented
+	Test3(); // error 004: function "Test3" is not implemented
+}