diff --git a/build-utils/layoutgen.sh b/build-utils/layoutgen.sh
index 804ea7252..db8e41afd 100755
--- a/build-utils/layoutgen.sh
+++ b/build-utils/layoutgen.sh
@@ -16,9 +16,9 @@ do
     grep '^layout_t layout_' $file | cut -d' ' -f2 | cut -d\; -f1 | while read layout
     do
         shortname=`echo $layout | cut -d _ -f2-`
-        echo "    {\"$shortname\", $layout},"
+        echo "    {\"$shortname\", sizeof(\"$shortname\") - 1, $layout},"
     done
 done
 
-echo "    {NULL, NULL}"
+echo "    {NULL, 0, NULL}"
 echo "};"
diff --git a/build-utils/widgetgen.sh b/build-utils/widgetgen.sh
index 037d3dbda..ae71b0bd3 100755
--- a/build-utils/widgetgen.sh
+++ b/build-utils/widgetgen.sh
@@ -10,9 +10,9 @@ do
     grep '^widget_constructor_t ' "$file" | cut -d' ' -f2 | cut -d\; -f1 | while read widget
     do
         shortname=`echo $widget | cut -d_ -f2`
-        echo "    {\"$shortname\", $widget},"
+        echo "    {\"$shortname\", sizeof(\"$shortname\") - 1, $widget},"
     done
 done
 
-echo "    {NULL, NULL}"
+echo "    {NULL, 0, NULL}"
 echo "};"
diff --git a/common/util.c b/common/util.c
index 1833e8b29..b72f61836 100644
--- a/common/util.c
+++ b/common/util.c
@@ -59,17 +59,18 @@ _warn(int line, const char *fct, const char *fmt, ...)
 /** Lookup for a function pointer from its name
  * in the given name_func_link_t list.
  * \param funcname Function name.
+ * \param len The function name length.
  * \param list Function and name link list.
  * \return Function pointer.
  */
 void *
-name_func_lookup(const char *funcname, const name_func_link_t *list)
+name_func_lookup(const char *funcname, size_t len, const name_func_link_t *list)
 {
     int i;
 
     if(funcname && list)
         for(i = 0; list[i].name; i++)
-            if(!a_strcmp(funcname, list[i].name))
+            if(len == list[i].len && !a_strcmp(funcname, list[i].name))
                 return list[i].func;
 
     return NULL;
diff --git a/common/util.h b/common/util.h
index 7dc3be8ab..b06169091 100644
--- a/common/util.h
+++ b/common/util.h
@@ -60,6 +60,7 @@ typedef enum
 typedef struct
 {
     const char *name;
+    size_t len;
     void *func;
 } name_func_link_t;
 
@@ -351,7 +352,7 @@ position_t position_fromstr(const char *, ssize_t);
 const char * position_tostr(position_t);
 orientation_t orientation_fromstr(const char *, ssize_t);
 const char * orientation_tostr(orientation_t);
-void *name_func_lookup(const char *, const name_func_link_t *);
+void *name_func_lookup(const char *, size_t, const name_func_link_t *);
 const char * name_func_rlookup(void *, const name_func_link_t *);
 void a_exec(const char *);
 char ** a_strsplit(const char *, ssize_t, char);
diff --git a/tag.c b/tag.c
index 1d03e8adf..7af7b6fca 100644
--- a/tag.c
+++ b/tag.c
@@ -271,7 +271,7 @@ tag_view_only_byindex(int screen, int dindex)
 static int
 luaA_tag_new(lua_State *L)
 {
-    size_t len;
+    size_t len, laylen;
     tag_t *tag;
     int ncol, nmaster;
     const char *name, *lay;
@@ -286,9 +286,9 @@ luaA_tag_new(lua_State *L)
     mwfact = luaA_getopt_number(L, 2, "mwfact", 0.5);
     ncol = luaA_getopt_number(L, 2, "ncol", 1);
     nmaster = luaA_getopt_number(L, 2, "nmaster", 1);
-    lay = luaA_getopt_string(L, 2, "layout", "tile");
+    lay = luaA_getopt_lstring(L, 2, "layout", "tile", &laylen);
 
-    layout = name_func_lookup(lay, LayoutList);
+    layout = name_func_lookup(lay, laylen, LayoutList);
 
     tag = tag_new(name, len,
                   layout,
@@ -430,8 +430,8 @@ luaA_tag_newindex(lua_State *L)
             tag_append_to_screen(*tag, &globalconf.screens[screen]);
         break;
       case A_TK_LAYOUT:
-        buf = luaL_checkstring(L, 3);
-        l = name_func_lookup(buf, LayoutList);
+        buf = luaL_checklstring(L, 3, &len);
+        l = name_func_lookup(buf, len, LayoutList);
         if(l)
             (*tag)->layout = l;
         else
diff --git a/widget.c b/widget.c
index c8ce4660c..4fa677fc1 100644
--- a/widget.c
+++ b/widget.c
@@ -329,10 +329,9 @@ luaA_widget_new(lua_State *L)
 
     luaA_checktable(L, 2);
 
-    align = luaA_getopt_lstring(L, 2, "align", "left", &len);
-    type = luaA_getopt_string(L, 2, "type", NULL);
+    type = luaA_getopt_lstring(L, 2, "type", NULL, &len);
 
-    if((wc = name_func_lookup(type, WidgetList)))
+    if((wc = name_func_lookup(type, len, WidgetList)))
     {
         w = p_new(widget_t, 1);
         wc(w);
@@ -344,6 +343,8 @@ luaA_widget_new(lua_State *L)
     }
 
     w->type = wc;
+
+    align = luaA_getopt_lstring(L, 2, "align", "left", &len);
     w->align_supported |= AlignLeft | AlignRight;
     w->align = draw_align_fromstr(align, len);