diff --git a/tools/CommandLineTools.hx b/tools/CommandLineTools.hx
index 00ec7f50c..9955bf841 100644
--- a/tools/CommandLineTools.hx
+++ b/tools/CommandLineTools.hx
@@ -328,7 +328,11 @@ class CommandLineTools {
 							
 							ProcessHelper.runCommand (Path.directory (hxmlPath), "haxe", [ Path.withoutDirectory (hxmlPath) ]);
 							
-							Sys.putEnv ("HAXELIB_PATH", cacheValue);
+							if (cacheValue != null) {
+								
+								Sys.putEnv ("HAXELIB_PATH", cacheValue);
+								
+							}
 							
 						}