diff --git a/vision/liblinear/linear.h b/vision/liblinear/linear.h
index 51ff608..87bd66a 100644
--- a/vision/liblinear/linear.h
+++ b/vision/liblinear/linear.h
@@ -19,7 +19,7 @@ struct problem
 	double bias;            /* < 0 if no bias term */  
 };
 
-enum { L2R_LR, L2R_L2LOSS_SVC_DUAL, L2R_L2LOSS_SVC, L2R_L1LOSS_SVC_DUAL, MCSVM_CS, L1R_L2LOSS_SVC, L1R_LR }; /* solver_type */
+enum solver_type { L2R_LR, L2R_L2LOSS_SVC_DUAL, L2R_L2LOSS_SVC, L2R_L1LOSS_SVC_DUAL, MCSVM_CS, L1R_L2LOSS_SVC, L1R_LR }; /* solver_type */
 
 struct parameter
 {