diff --git a/config.m4 b/config.m4
index 053b5fa..935a3db 100644
--- a/config.m4
+++ b/config.m4
@@ -86,6 +86,11 @@ if test "$PHP_EXCEL" != "no"; then
     -L$EXCEL_LIBDIR
   ])
 
+  PHP_CHECK_LIBRARY(xl,xlBookSetKeyA,
+  [
+    AC_DEFINE(HAVE_LIBXL_SETKEY,1,[ ])
+  ],[],[])
+
   if test `grep -c FILLPATTERN_HORSTRIPE $EXCEL_INCDIR/enum.h` -eq 1; then
     AC_DEFINE(HAVE_LIBXL_243_PLUS,1,[ ])
   fi
diff --git a/config.w32 b/config.w32
index 2954d78..858acfe 100644
--- a/config.w32
+++ b/config.w32
@@ -5,6 +5,7 @@ if (PHP_EXCEL != "no") {
 		EXTENSION("excel", "excel.c");
 		AC_DEFINE('HAVE_EXCELLIB', 1, 'Have LibXL library');
 		AC_DEFINE('HAVE_LIBXL_243_PLUS', 1, 'Have LibXL version 2.4.3 or later');
+		AC_DEFINE("HAVE_LIBXL_SETKEY", 1, "non-source libxl build");
 		AC_DEFINE("EXCEL_WITH_LIBXML", 1, "libxml support");
 	} else {
 		WARNING("excel not enabled; libraries and headers not found");
diff --git a/excel.c b/excel.c
index 8ac4f66..fdfe396 100644
--- a/excel.c
+++ b/excel.c
@@ -79,8 +79,10 @@ ZEND_DECLARE_MODULE_GLOBALS(excel)
 static PHP_GINIT_FUNCTION(excel);
 
 PHP_INI_BEGIN()
+#if defined(HAVE_LIBXL_SETKEY)
 	STD_PHP_INI_ENTRY("excel.license_name", NULL, PHP_INI_ALL, OnUpdateString, ini_license_name, zend_excel_globals, excel_globals)
 	STD_PHP_INI_ENTRY("excel.license_key", NULL, PHP_INI_ALL, OnUpdateString, ini_license_key, zend_excel_globals, excel_globals)
+#endif
 	STD_PHP_INI_ENTRY("excel.skip_empty", "0", PHP_INI_ALL, OnUpdateLong, ini_skip_empty, zend_excel_globals, excel_globals)
 PHP_INI_END()
 
@@ -387,6 +389,19 @@ static wchar_t * _php_excel_to_wide(const char *string, size_t len, size_t *out_
 #define EXCEL_METHOD(class_name, function_name) \
 	PHP_METHOD(Excel ## class_name, function_name)
 
+
+/* {{{ proto bool ExcelBook::requiresKey()
+	true if license key is required. */
+EXCEL_METHOD(Book, requiresKey)
+{
+#if defined(HAVE_LIBXL_SETKEY)
+	RETURN_BOOL(1);
+#else
+	RETURN_BOOL(0);
+#endif
+}
+/* }}} */
+
 /* {{{ proto bool ExcelBook::load(string data)
 	Load Excel data string. */
 EXCEL_METHOD(Book, load)
@@ -1240,6 +1255,7 @@ EXCEL_METHOD(Book, __construct)
 		RETURN_FALSE;
 	}
 #endif
+#if defined(HAVE_LIBXL_SETKEY)
 	if (!name_len) {
 		if (INI_STR("excel.license_name") && INI_STR("excel.license_key")) {
 			name = INI_STR("excel.license_name");
@@ -1252,6 +1268,7 @@ EXCEL_METHOD(Book, __construct)
 #endif
 		}
 	}
+#endif
 
 	BOOK_FROM_OBJECT(book, object);
 #ifdef LIBXL_VERSION
@@ -1263,6 +1280,9 @@ EXCEL_METHOD(Book, __construct)
 		} else {
 			RETURN_FALSE;
 		}
+#if !defined(HAVE_LIBXL_SETKEY)
+		return;
+#endif
 		if (!name_len && !key_len) {
 			return;
 		}
diff --git a/tests/088.phpt b/tests/088.phpt
index a2fedae..7678d6b 100644
--- a/tests/088.phpt
+++ b/tests/088.phpt
@@ -31,7 +31,7 @@ bool(true)
 bool(false)
 bool(false)
 bool(false)
-string(5) "=3+4"
-string(1) ""
-string(2) "3"
+string(4) "=3+4"
+string(0) ""
+string(1) "3"
 OK