diff --git a/ogzaf/macro_params.py b/ogzaf/macro_params.py
index d89a22c..88306b0 100644
--- a/ogzaf/macro_params.py
+++ b/ogzaf/macro_params.py
@@ -33,7 +33,7 @@ def get_macro_params(
     # initialize a dictionary of parameters
     macro_parameters = {}
     # baseline date formatted for World Bank data
-    baseline_YYYYQ = data_end_date.strftime("%YQ%q")
+    baseline_YYYYQ = data_end_date.strftime(r"%YQ%q")
 
     """
     Retrieve data from the World Bank World Development Indicators.