diff --git a/pygmt/src/config.py b/pygmt/src/config.py
index 0fcf181891c..0bedf9fe091 100644
--- a/pygmt/src/config.py
+++ b/pygmt/src/config.py
@@ -207,7 +207,7 @@ def __enter__(self):
     def __exit__(self, exc_type, exc_value, traceback):
         # revert to initial values
         arg_str = " ".join(
-            [f"{key}={value}" for key, value in self.old_defaults.items()]
+            [f'{key}="{value}"' for key, value in self.old_defaults.items()]
         )
         with Session() as lib:
             lib.call_module(module="set", args=arg_str)
diff --git a/pygmt/tests/test_config.py b/pygmt/tests/test_config.py
index a1e591e8220..fbaddd323e4 100644
--- a/pygmt/tests/test_config.py
+++ b/pygmt/tests/test_config.py
@@ -72,8 +72,13 @@ def test_config_format_date_map():
 
     Note the space in 'o dd', this acts as a regression test for
     https://github.com/GenericMappingTools/pygmt/issues/247.
+
+    Setting FORMAT_DATE_MAP="yyyy mm dd" as a regression test for
+    https://github.com/GenericMappingTools/pygmt/issues/2298.
     """
     fig = Figure()
+    # Set FORMAT_DATE_MAP to "yyyy mm dd" which contains whitespaces.
+    config(FORMAT_DATE_MAP="yyyy mm dd")
     with config(FORMAT_DATE_MAP="o dd"):
         fig.basemap(
             region=["1969-7-21T", "1969-7-23T", 0, 1],