diff --git a/src/qiskit_qec/circuits/repetition_code.py b/src/qiskit_qec/circuits/repetition_code.py
index b08ccda4..b8500d23 100644
--- a/src/qiskit_qec/circuits/repetition_code.py
+++ b/src/qiskit_qec/circuits/repetition_code.py
@@ -349,7 +349,7 @@ def string2raw_logicals(self, string):
         Returns:
             list: Raw values for logical operators that correspond to nodes.
         """
-        return string.split(' ')[0][-1]
+        return string.split(" ", maxsplit=1)[0][-1]
 
     def check_nodes(self, nodes, ignore_extra_boundary=False, minimal=False):
         """
diff --git a/test/code_circuits/test_rep_codes.py b/test/code_circuits/test_rep_codes.py
index 3b3202e2..7a76430c 100644
--- a/test/code_circuits/test_rep_codes.py
+++ b/test/code_circuits/test_rep_codes.py
@@ -555,7 +555,7 @@ def clustering_decoder_test(
                 for j, z_logical in enumerate(decoder.measured_logicals):
                     error = corrected_z_logicals[j] != 1
                     if error:
-                        error_num = string.split(" ")[0].count("0")
+                        error_num = string.split(" ", maxsplit=1)[0].count("0")
                         if error_num < min_error_num:
                             min_error_num = error_num
                             min_error_string = string