diff --git a/builders/builder.py b/builders/builder.py
index c19766e..bb76103 100644
--- a/builders/builder.py
+++ b/builders/builder.py
@@ -46,8 +46,8 @@ def _which(program):
         return os.path.isfile(fpath) and os.access(fpath, os.X_OK)
 
     fpath, fname = os.path.split(program)
-    if fpath and is_exe(program):
-        return program
+    if fpath and is_exe(os.path.abspath(program)):
+        return os.path.abspath(program)
     else:
         for path in os.environ['PATH'].split(os.pathsep):
             path = path.strip('"')