diff --git a/tests/bugs/step/bug31301 b/tests/bugs/step/bug31301
index a4357c7874..6dc9cebb19 100644
--- a/tests/bugs/step/bug31301
+++ b/tests/bugs/step/bug31301
@@ -1,5 +1,7 @@
 testreadstep [locate_data_file bug31301.stp] s
-testwritestep bug31301_1.stp s
-testreadstep bug31301_1.stp s1
+set aTmpFile "$imagedir/${casename}.stp"
+testwritestep "$aTmpFile" s
+testreadstep  "$aTmpFile" s1
+file delete   "$aTmpFile"
 checkshape s1 f
-checkmaxtol s1 -ref 0.0078
\ No newline at end of file
+checkmaxtol s1 -ref 0.0078
diff --git a/tests/bugs/step/bug31301_2 b/tests/bugs/step/bug31301_2
index df99f055d1..7afa9960f1 100644
--- a/tests/bugs/step/bug31301_2
+++ b/tests/bugs/step/bug31301_2
@@ -1,5 +1,7 @@
 restore  [locate_data_file bug31301_2.brep] s
-testwritestep bug31301_1.stp s
-testreadstep bug31301_1.stp s1
+set aTmpFile "$imagedir/${casename}.stp"
+testwritestep "$aTmpFile" s
+testreadstep  "$aTmpFile" s1
+file delete   "$aTmpFile"
 checkshape s1 f
-checkmaxtol s1 -ref 0.000247
\ No newline at end of file
+checkmaxtol s1 -ref 0.000247
diff --git a/tests/bugs/step/bug31485 b/tests/bugs/step/bug31485
index db3cc1826e..27d3538ab2 100644
--- a/tests/bugs/step/bug31485
+++ b/tests/bugs/step/bug31485
@@ -7,9 +7,10 @@ brestore [locate_data_file bug31485.brep] a
 
 param write.step.nonmanifold 1
 
-testwritestep comp_nonmanifold.step a
-testreadstep comp_nonmanifold.step result
+set aTmpFile "$imagedir/${casename}.step"
+testwritestep "$aTmpFile" a
+testreadstep  "$aTmpFile" result
+file delete   "$aTmpFile"
 
 checkshape result
-
 checknbshapes result -face 3
diff --git a/tests/bugs/step/bug31617 b/tests/bugs/step/bug31617
index b3ba1e2fed..1724d5d442 100644
--- a/tests/bugs/step/bug31617
+++ b/tests/bugs/step/bug31617
@@ -7,9 +7,10 @@ brestore [locate_data_file bug31617.brep] a
 
 param write.step.nonmanifold 1
 
-testwritestep comp_nonmanifold.step a
-testreadstep comp_nonmanifold.step result
+set aTmpFile "$imagedir/${casename}.step"
+testwritestep "$aTmpFile" a
+testreadstep  "$aTmpFile" result
+file delete   "$aTmpFile"
 
 checkshape result
-
 checknbshapes result -ref [lrange [nbshapes a] 11 16]
diff --git a/tests/de_mesh/shape_write_stl/B1 b/tests/de_mesh/shape_write_stl/B1
index 2747c6ddc8..4ecf0c097a 100644
--- a/tests/de_mesh/shape_write_stl/B1
+++ b/tests/de_mesh/shape_write_stl/B1
@@ -1,7 +1,9 @@
 sphere s 10
 tessellate result s 100 100
 XProgress +t
-set out [writestl result s.stl]
+set aTmpFile "$imagedir/${casename}.stl"
+set out [writestl result "$aTmpFile"]
+file delete "$aTmpFile"
 
 set expected {
   {Progress: 0%}