diff --git a/optimum/intel/openvino/configuration.py b/optimum/intel/openvino/configuration.py
index badfd6439..3cf2c3b41 100644
--- a/optimum/intel/openvino/configuration.py
+++ b/optimum/intel/openvino/configuration.py
@@ -471,7 +471,7 @@ def post_init(self):
             if self.gptq:
                 raise ValueError("The GPTQ algorithm is not supported for 'mxfp4' weight format")
 
-        if self.weight_format in "nf4" and self.bits != 4:
+        if self.weight_format == "nf4" and self.bits != 4:
             raise ValueError(
                 f"When applying weight compression with 'nf4' weight format the `bits` parameters must be set to 4, but found {self.bits}"
             )