diff --git a/qiskit/qasm3/exporter.py b/qiskit/qasm3/exporter.py
index 663c2d38502e..0fbd0614d4e4 100644
--- a/qiskit/qasm3/exporter.py
+++ b/qiskit/qasm3/exporter.py
@@ -1302,7 +1302,7 @@ def visit_value(self, node, /):
                 return ast.DurationLiteral(node.value[0], ast.DurationUnit.MICROSECOND)
             if isinstance(node.value, Duration.ms):
                 return ast.DurationLiteral(node.value[0], ast.DurationUnit.MILLISECOND)
-            if isinstance(node.value, Duration.sec):
+            if isinstance(node.value, Duration.s):
                 return ast.DurationLiteral(node.value[0], ast.DurationUnit.SECOND)
         raise RuntimeError(f"unhandled Value type '{node}'")
 
diff --git a/qiskit/qpy/binary_io/value.py b/qiskit/qpy/binary_io/value.py
index 4f7a8a1297f8..5f2d72046322 100644
--- a/qiskit/qpy/binary_io/value.py
+++ b/qiskit/qpy/binary_io/value.py
@@ -438,7 +438,7 @@ def _write_duration(file_obj, duration: Duration):
     elif isinstance(duration, Duration.ms):
         file_obj.write(type_keys.CircuitDuration.MS)
         file_obj.write(struct.pack(formats.DURATION_MS_PACK, *formats.DURATION_MS(duration[0])))
-    elif isinstance(duration, Duration.sec):
+    elif isinstance(duration, Duration.s):
         file_obj.write(type_keys.CircuitDuration.S)
         file_obj.write(struct.pack(formats.DURATION_S_PACK, *formats.DURATION_S(duration[0])))
     else:
diff --git a/qiskit/qpy/type_keys.py b/qiskit/qpy/type_keys.py
index 20efa48a504b..6f758812ccba 100644
--- a/qiskit/qpy/type_keys.py
+++ b/qiskit/qpy/type_keys.py
@@ -583,7 +583,7 @@ def assign(cls, obj):
             return cls.US
         elif isinstance(obj, Duration.ms):
             return cls.MS
-        elif isinstance(obj, Duration.sec):
+        elif isinstance(obj, Duration.s):
             return cls.S
         else:
             raise exceptions.QpyError(