diff --git a/src/include/string.h b/src/include/string.h
index 1c07af0ca5..3d056818cc 100644
--- a/src/include/string.h
+++ b/src/include/string.h
@@ -104,6 +104,11 @@ static inline int isxdigit(int c)
 		(c >= 'A' && c <= 'F'));
 }
 
+static inline int isupper(int c)
+{
+	return (c >= 'A' && c <= 'Z');
+}
+
 static inline int islower(int c)
 {
 	return (c >= 'a' && c <= 'z');
@@ -115,4 +120,11 @@ static inline int toupper(int c)
                 c -= 'a'-'A';
         return c;
 }
+
+static inline int tolower(int c)
+{
+        if (isupper(c))
+                c -= 'A'-'a';
+        return c;
+}
 #endif /* STRING_H */