diff --git a/bfps/__main__.py b/bfps/__main__.py
index bdc74edf32fb45699f22c07b8d62f307a15400fd..6d788bd921d52155d891a47289c234b6dfb4bc43 100644
--- a/bfps/__main__.py
+++ b/bfps/__main__.py
@@ -64,7 +64,7 @@ def main():
         precision = 'double'
     else:
         precision = 'single'
-    c = eval('{0}(fluid_precision = {1})'.format(opt.base_class, precision))
+    c = eval('{0}(fluid_precision = \'{1}\')'.format(opt.base_class, precision))
     c.launch(args = sys.argv[2:])
     return None