diff --git a/src/base/str.hh b/src/base/str.hh
index 52ab977..61022bd 100644
--- a/src/base/str.hh
+++ b/src/base/str.hh
@@ -1,4 +1,7 @@
 /*
+ * Copyright (c) 2018 ARM Limited
+ * All rights reserved
+ *
  * Copyright (c) 2001-2005 The Regents of The University of Michigan
  * All rights reserved.
  *
@@ -102,10 +105,11 @@
  * @{
  *
  * @name String to number helper functions for signed and unsigned
- *       integeral type, as well as floating-point types.
+ *       integeral type, as well as enums and floating-point types.
  */
 template <class T>
-typename std::enable_if<std::is_integral<T>::value &&
+typename std::enable_if<(std::is_integral<T>::value ||
+                        std::is_enum<T>::value) &&
                         std::is_signed<T>::value, T>::type
 __to_number(const std::string &value)
 {
@@ -117,7 +121,8 @@
 }
 
 template <class T>
-typename std::enable_if<std::is_integral<T>::value &&
+typename std::enable_if<(std::is_integral<T>::value ||
+                        std::is_enum<T>::value) &&
                         !std::is_signed<T>::value, T>::type
 __to_number(const std::string &value)
 {