diff --git a/Source/driver/Castro_util.H b/Source/driver/Castro_util.H
index 9dd3c4606b..c6162b0190 100644
--- a/Source/driver/Castro_util.H
+++ b/Source/driver/Castro_util.H
@@ -174,7 +174,7 @@ Real distance(GeometryData const& geomdata, GpuArray<Real, 3>& loc)
         return std::sqrt(loc[0]*loc[0] + loc[1]*loc[1]);
     }
 
-    return loc[0];
+    return std::abs(loc[0]);
 }
 
 
diff --git a/Source/driver/Derive.cpp b/Source/driver/Derive.cpp
index a59cdaccda..78a1dfcc35 100644
--- a/Source/driver/Derive.cpp
+++ b/Source/driver/Derive.cpp
@@ -661,7 +661,7 @@ extern "C"
           der(i,j,k,0) = (-dat(i,j,k,1)*loc[1] + dat(i,j,k,2)*loc[0]) / (dat(i,j,k,0)*r);
 #endif
         } else {
-            Real r = distance(geomdata, loc);
+          Real r = distance(geomdata, loc);
 
           // we really mean just the velocity component that is
           // perpendicular to radial, and in general 3-d (e.g. a