diff --git a/include/core/problem/problem.h b/include/core/problem/problem.h
index 0d8539fd05d64803327ab3ceafba4feb0763d1c3..0ba4badcdba1e22b15d5ab228673aaf363b7954d 100644
--- a/include/core/problem/problem.h
+++ b/include/core/problem/problem.h
@@ -202,7 +202,7 @@ class Problem : public std::enable_shared_from_this<Problem>
                              const VectorComposite& _cov   = VectorComposite());
         FrameBasePtr applyPriorOptions(const TimeStamp& _ts);
         FrameBasePtr setPriorFactor(const VectorComposite &_state,
-                                    const VectorComposite &_cov,
+                                    const VectorComposite &_sigma,
                                     const TimeStamp &_ts,
                                     const double &_time_tol);
         FrameBasePtr setPriorFix(const VectorComposite &_state,
diff --git a/src/problem/problem.cpp b/src/problem/problem.cpp
index ef1f8b5bcfd7957cbdc725b8d4c5db0fbf134aa5..09533b1a8726ab6ee74c7bd908c6746264b45a3b 100644
--- a/src/problem/problem.cpp
+++ b/src/problem/problem.cpp
@@ -1082,11 +1082,11 @@ FrameBasePtr Problem::applyPriorOptions(const TimeStamp& _ts)
 }
 
 FrameBasePtr Problem::setPriorFactor(const VectorComposite &_state,
-                                     const VectorComposite &_cov,
+                                     const VectorComposite &_sigma,
                                      const TimeStamp &_ts,
                                      const double &_time_tol)
 {
-    setPriorOptions("factor", _time_tol, _state, _cov);
+    setPriorOptions("factor", _time_tol, _state, _sigma);
     return applyPriorOptions(_ts);
 }