diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index e988fa935b3c..b3c4b8dac1ce 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -447,11 +447,13 @@ static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
 static inline struct i2c_adapter *
 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
 {
+#if IS_ENABLED(I2C_MUX)
 	struct device *parent = adapter->dev.parent;
 
 	if (parent != NULL && parent->type == &i2c_adapter_type)
 		return to_i2c_adapter(parent);
 	else
+#endif
 		return NULL;
 }