diff --git a/include/cantera/oneD/OneDim.h b/include/cantera/oneD/OneDim.h
index fa158c3f8..95068972d 100644
--- a/include/cantera/oneD/OneDim.h
+++ b/include/cantera/oneD/OneDim.h
@@ -162,7 +162,7 @@ public:
     /**
      * Evaluate the multi-domain residual function
      *
-     * @param j       if j > 0, only evaluate residual for points j-1, j,
+     * @param j       if j != npos, only evaluate residual for points j-1, j,
      *                and j + 1; otherwise, evaluate at all grid points.
      * @param x       solution vector
      * @param r       on return, contains the residual vector
diff --git a/include/cantera/oneD/StFlow.h b/include/cantera/oneD/StFlow.h
index 4f257a9ef..53ac8e320 100644
--- a/include/cantera/oneD/StFlow.h
+++ b/include/cantera/oneD/StFlow.h
@@ -268,10 +268,10 @@ public:
 
     /*!
      *  Evaluate the residual function for axisymmetric stagnation flow. If
-     *  jpt is less than zero, the residual function is evaluated at all grid
-     *  points. If jpt >= 0, then the residual function is only evaluated at
-     *  grid points jpt-1, jpt, and jpt+1. This option is used to efficiently
-     *  evaluate the Jacobian numerically.
+     *  j == npos, the residual function is evaluated at all grid points.
+     *  Otherwise, the residual function is only evaluated at grid points
+     *  j-1, j, and j+1. This option is used to efficiently evaluate the
+     *  Jacobian numerically.
      */
     virtual void eval(size_t j, doublereal* x, doublereal* r,
                       integer* mask, doublereal rdt);