diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5cd44af1..bffe9813 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - drill maps: uses drill instead of drl
   - dril: uses drill instead of drl, used in gbr and drl.
   - position: no -pos in CSVs
+  - step: adds -3D
 
 ## [0.5.0] - 2020-07-11
 ### Changed
diff --git a/kiplot/out_step.py b/kiplot/out_step.py
index fc805371..2ef8abd4 100644
--- a/kiplot/out_step.py
+++ b/kiplot/out_step.py
@@ -25,8 +25,8 @@ class STEPOptions(BaseOptions):
             """ used to exclude 3D models for components with 'virtual' attribute """
             self.min_distance = -1
             """ the minimum distance between points to treat them as separate ones (-1 is KiCad default: 0.01 mm) """
-            self.output = ''
-            """ name for the generated STEP file (the name of the PCB if empty) """  # pragma: no cover
+            self.output = '%f-%i.%x'
+            """ name for the generated STEP file (%i='3D' %x='step') """  # pragma: no cover
 
     @property
     def origin(self):
@@ -40,10 +40,7 @@ class STEPOptions(BaseOptions):
 
     def run(self, output_dir, board):
         # Output file name
-        output = self.output
-        if not output:
-            output = os.path.splitext(os.path.basename(GS.pcb_file))[0]+'.step'
-        output = os.path.abspath(os.path.join(output_dir, output))
+        output = self.expand_filename(output_dir, self.output, '3D', 'step')
         # Make units explicit
         if self.metric_units:
             units = 'mm'
diff --git a/tests/test_plot/test_step.py b/tests/test_plot/test_step.py
index 03e57f23..9c192a36 100644
--- a/tests/test_plot/test_step.py
+++ b/tests/test_plot/test_step.py
@@ -27,7 +27,7 @@ def test_step_1():
     ctx = context.TestContext('STEP_1', prj, 'step_simple', STEP_DIR)
     ctx.run()
     # Check all outputs are there
-    ctx.expect_out_file(os.path.join(STEP_DIR, prj+'.step'))
+    ctx.expect_out_file(os.path.join(STEP_DIR, prj+'-3D.step'))
     ctx.clean_up()
 
 
@@ -36,7 +36,7 @@ def test_step_2():
     ctx = context.TestContext('STEP_2', prj, 'step_simple_2', STEP_DIR)
     ctx.run()
     # Check all outputs are there
-    ctx.expect_out_file(os.path.join(STEP_DIR, prj+'.step'))
+    ctx.expect_out_file(os.path.join(STEP_DIR, prj+'-3D.step'))
     ctx.clean_up()
 
 
diff --git a/tests/yaml_samples/step_simple_3.kiplot.yaml b/tests/yaml_samples/step_simple_3.kiplot.yaml
index a3d75376..dd57b9bc 100644
--- a/tests/yaml_samples/step_simple_3.kiplot.yaml
+++ b/tests/yaml_samples/step_simple_3.kiplot.yaml
@@ -11,4 +11,4 @@ outputs:
       origin: grid         # "grid" or "drill" o "X,Y" i.e. 3.2,-10
       no_virtual: true     # exclude 3D models for components with 'virtual' attribute
       min_distance: 0.0004 # Minimum distance between points to treat them as separate ones (default 0.01 mm)
-      #output: project.step
+      output: '%f.%x'