diff --git a/src/coreprofiles.f90 b/src/coreprofiles.f90
index a9afd97..e3a43da 100644
--- a/src/coreprofiles.f90
+++ b/src/coreprofiles.f90
@@ -371,12 +371,16 @@ contains
     call dens_spline%init(data%psrad, data%derad, n, range=[zero, data%psrad(n)], &
                           tension=params%sspld, err=err)
 
-    ! if failed, re-fit with an interpolating spline (zero tension)
+    ! Tension is very small, re-fit with an interpolating spline
     if (err == -1) then
-        call log_warning('density fit failed with error -1: re-fitting with '// &
-                         'zero tension', mod='coreprofiles', proc='density')
+        call log_warning('re-fitting with density curve with zero tension', &
+                         mod='coreprofiles', proc='density')
         call dens_spline%init(data%psrad, data%derad, n, &
                               range=[zero, data%psrad(n)], tension=zero)
+    else if (err > 0) then
+        write (msg, '(a, g0)') 'density fit failed with error ', err
+        call log_error(msg, mod='coreprofiles', proc='density')
+        call exit(1)
     end if
 
     ! Computation of the polynomial tail parameters