diff --git a/arc/common.py b/arc/common.py
index b504f5d567..04633a9580 100644
--- a/arc/common.py
+++ b/arc/common.py
@@ -1864,3 +1864,16 @@ def calculate_arrhenius_rate_coefficient(A: Union[int, float, Sequence[float], n
         raise ValueError("All temperature values must be positive")
     exp_arg = -Ea_arr / (R * T_arr)
     return A_arr * np.power(T_arr, n_arr) * np.exp(exp_arg)
+
+
+def fill_in_the_blanks(folder_name: str):
+    """
+    Adding backslashes before spaces in the folder name.
+
+    Args:
+        folder_name (str): The string directory we want to modify.
+
+    Returns:
+        str: Modified folder name.
+    """
+    return folder_name.replace(" ", "\ ")
diff --git a/arc/common_test.py b/arc/common_test.py
index 2a5c9b417a..aca01e0c18 100644
--- a/arc/common_test.py
+++ b/arc/common_test.py
@@ -1391,6 +1391,19 @@ def test_calculate_arrhenius_rate_coefficient(self):
             with self.assertRaises(ValueError):
                 common.calculate_arrhenius_rate_coefficient(A=1e12, n=0.5, Ea=10, T=bad_T, Ea_units='kJ/mol')
 
+    def test_fill_in_the_blanks(self):
+        """Test the fill_in_the_blanks() function"""
+        ex1 = "name"
+        ex2 = "name1 name2"
+        ex3 = "name 1 name2"
+        ex4 = "name 1  name2"
+        ex5 = "/home/user/Code/ARC/Projects/project name/calcs/file.sh"
+        self.assertEqual(common.fill_in_the_blanks(ex1), "name")
+        self.assertEqual(common.fill_in_the_blanks(ex2), "name1\\ name2")
+        self.assertEqual(common.fill_in_the_blanks(ex3), "name\\ 1\\ name2")
+        self.assertEqual(common.fill_in_the_blanks(ex4), "name\\ 1\\ \\ name2")
+        self.assertEqual(common.fill_in_the_blanks(ex5), "/home/user/Code/ARC/Projects/project\\ name/calcs/file.sh")
+
     @classmethod
     def tearDownClass(cls):
         """
diff --git a/arc/main.py b/arc/main.py
index e8c68a8057..1bf93ada17 100644
--- a/arc/main.py
+++ b/arc/main.py
@@ -21,6 +21,7 @@
                         ARC_PATH,
                         check_ess_settings,
                         delete_check_files,
+                        fill_in_the_blanks,
                         get_logger,
                         globalize_path,
                         initialize_job_types,
@@ -280,6 +281,7 @@ def __init__(self,
         self.verbose = verbose
         self.project_directory = project_directory if project_directory is not None \
             else os.path.join(ARC_PATH, 'Projects', self.project)
+        self.project_directory = fill_in_the_blanks(self.project_directory)
         if not os.path.exists(self.project_directory):
             os.makedirs(self.project_directory)
         self.output = output