diff --git a/raster/r.sim/r.sim.sediment/main.c b/raster/r.sim/r.sim.sediment/main.c
index d0197c2abb1..b3945946eae 100644
--- a/raster/r.sim/r.sim.sediment/main.c
+++ b/raster/r.sim/r.sim.sediment/main.c
@@ -286,7 +286,9 @@ int main(int argc, char *argv[])
     parm.threads->answer = NUM_THREADS;
     parm.threads->required = NO;
     parm.threads->description =
-        _("Number of threads which will be used for parallel compute");
+        _("Number of threads which will be used for parallel computation. "
+          "Increasing the number of threads does not really speed up "
+          "the simulation.");
     parm.threads->guisection = _("Parameters");
 
     if (G_parser(argc, argv))
diff --git a/raster/r.sim/r.sim.water/main.c b/raster/r.sim/r.sim.water/main.c
index fa6f926980d..2a30f5de0d2 100644
--- a/raster/r.sim/r.sim.water/main.c
+++ b/raster/r.sim/r.sim.water/main.c
@@ -333,8 +333,8 @@ int main(int argc, char *argv[])
     parm.threads->required = NO;
     parm.threads->description =
         _("Number of threads which will be used for parallel computation. "
-          "Increasing "
-          "the number of threads does not really speed up the simulation.");
+          "Increasing the number of threads does not really speed up "
+          "the simulation.");
     parm.threads->guisection = _("Parameters");
 
     if (G_parser(argc, argv))