diff --git a/src/muz_qe/dl_instruction.cpp b/src/muz_qe/dl_instruction.cpp
index 401a42e98..478af3127 100644
--- a/src/muz_qe/dl_instruction.cpp
+++ b/src/muz_qe/dl_instruction.cpp
@@ -452,7 +452,7 @@ namespace datalog {
 
 
     class instr_filter_identical : public instruction {
-        typedef vector<unsigned> column_vector;
+        typedef unsigned_vector column_vector;
         reg_idx m_reg;
         column_vector m_cols;
     public:
@@ -651,7 +651,7 @@ namespace datalog {
 
 
     class instr_project_rename : public instruction {
-        typedef vector<unsigned> column_vector;
+        typedef unsigned_vector column_vector;
         bool m_projection;
         reg_idx m_src;
         column_vector m_cols;
@@ -830,7 +830,7 @@ namespace datalog {
 
 
     class instr_filter_by_negation : public instruction {
-        typedef vector<unsigned> column_vector;
+        typedef unsigned_vector column_vector;
         reg_idx m_tgt;
         reg_idx m_neg_rel;
         column_vector m_cols1;