diff --git a/src/Composer/Package/Version/VersionParser.php b/src/Composer/Package/Version/VersionParser.php
index 9c6e35812..2440b6b6a 100644
--- a/src/Composer/Package/Version/VersionParser.php
+++ b/src/Composer/Package/Version/VersionParser.php
@@ -372,7 +372,7 @@ class VersionParser
         $pairs = array_values($pairs);
         $result = array();
 
-        for ($i = 0; $i < count($pairs); $i++) {
+        for ($i = 0, $count = count($pairs); $i < $count; $i++) {
             $pair = preg_replace('{^([^=: ]+)[=: ](.*)$}', '$1 $2', trim($pairs[$i]));
             if (false === strpos($pair, ' ') && isset($pairs[$i+1]) && false === strpos($pairs[$i+1], '/')) {
                 $pair .= ' '.$pairs[$i+1];