diff --git a/bitrise/util_test.go b/bitrise/util_test.go
index ae46e872..37d77cc5 100644
--- a/bitrise/util_test.go
+++ b/bitrise/util_test.go
@@ -305,3 +305,199 @@ workflows:
 	require.Error(t, err)
 	require.Equal(t, 0, len(warnings))
 }
+
+func TestConfigModelFromYAMLFileContent_StepListValidation(t *testing.T) {
+	tests := []struct {
+		name    string
+		config  string
+		wantErr string
+	}{
+		{
+			name: "Invalid bitrise.yml: step bundle in a step bundle's steps list",
+			config: `
+format_version: '11'
+default_step_lib_source: https://github.com/bitrise-io/bitrise-steplib.git
+step_bundles:
+  build: {}
+  test:
+    steps:
+    - bundle::build: {}`,
+			wantErr: "step bundle is not allowed in a step list",
+		},
+		{
+			name: "Invalid bitrise.yml: with group in a step bundle's steps list",
+			config: `
+format_version: '11'
+default_step_lib_source: https://github.com/bitrise-io/bitrise-steplib.git
+step_bundles:
+  test:
+    steps:
+    - with: {}`,
+			wantErr: "'with' group is not allowed in a step list",
+		},
+		{
+			name: "Invalid bitrise.yml: step bundle in a 'with' group's steps list",
+			config: `
+format_version: '11'
+default_step_lib_source: https://github.com/bitrise-io/bitrise-steplib.git
+services:
+  postgres:
+    image: postgres:13
+workflows:
+  primary:
+    steps:
+    - with:
+        services:
+        - postgres
+        steps:
+        - bundle::test: {}`,
+			wantErr: "step bundle is not allowed in a step list",
+		},
+		{
+			name: "Invalid bitrise.yml: with group in a 'with' group's steps list",
+			config: `
+format_version: '11'
+default_step_lib_source: https://github.com/bitrise-io/bitrise-steplib.git
+services:
+  postgres:
+    image: postgres:13
+workflows:
+  primary:
+    steps:
+    - with:
+        services:
+        - postgres
+        steps:
+        - with: {}`,
+			wantErr: "'with' group is not allowed in a step list",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, warns, err := ConfigModelFromFileContent([]byte(tt.config), false)
+			require.Equal(t, []string(nil), warns)
+			if tt.wantErr != "" {
+				require.EqualError(t, err, tt.wantErr)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}
+
+func TestConfigModelFromJSONFileContent_StepListValidation(t *testing.T) {
+	tests := []struct {
+		name    string
+		config  string
+		wantErr string
+	}{
+		{
+			name: "Invalid bitrise.yml: step bundle in a step bundle's steps list",
+			config: `{
+  "format_version": "11",
+  "default_step_lib_source": "https://github.com/bitrise-io/bitrise-steplib.git",
+  "step_bundles": {
+    "build": {},
+    "test": {
+      "steps": [
+        {
+          "bundle::build": {}
+        }
+      ]
+    }
+  }
+}`,
+			wantErr: "step bundle is not allowed in a step list",
+		},
+		{
+			name: "Invalid bitrise.yml: with group in a step bundle's steps list",
+			config: `{
+  "format_version": "11",
+  "default_step_lib_source": "https://github.com/bitrise-io/bitrise-steplib.git",
+  "step_bundles": {
+    "test": {
+      "steps": [
+        {
+          "with": {}
+        }
+      ]
+    }
+  }
+}`,
+			wantErr: "'with' group is not allowed in a step list",
+		},
+		{
+			name: "Invalid bitrise.yml: step bundle in a 'with' group's steps list",
+			config: `{
+  "format_version": "11",
+  "default_step_lib_source": "https://github.com/bitrise-io/bitrise-steplib.git",
+  "services": {
+    "postgres": {
+      "image": "postgres:13"
+    }
+  },
+  "workflows": {
+    "primary": {
+      "steps": [
+        {
+          "with": {
+            "services": [
+              "postgres"
+            ],
+            "steps": [
+              {
+                "bundle::test": {}
+              }
+            ]
+          }
+        }
+      ]
+    }
+  }
+}`,
+			wantErr: "step bundle is not allowed in a step list",
+		},
+		{
+			name: "Invalid bitrise.yml: with group in a 'with' group's steps list",
+			config: `{
+  "format_version": "11",
+  "default_step_lib_source": "https://github.com/bitrise-io/bitrise-steplib.git",
+  "services": {
+    "postgres": {
+      "image": "postgres:13"
+    }
+  },
+  "workflows": {
+    "primary": {
+      "steps": [
+        {
+          "with": {
+            "services": [
+              "postgres"
+            ],
+            "steps": [
+              {
+                "with": {}
+              }
+            ]
+          }
+        }
+      ]
+    }
+  }
+}`,
+			wantErr: "'with' group is not allowed in a step list",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, warns, err := ConfigModelFromFileContent([]byte(tt.config), true)
+			require.Equal(t, []string(nil), warns)
+			if tt.wantErr != "" {
+				require.EqualError(t, err, tt.wantErr)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}
diff --git a/models/models_methods.go b/models/models_methods.go
index c56df340..925668c8 100644
--- a/models/models_methods.go
+++ b/models/models_methods.go
@@ -1306,6 +1306,47 @@ func (stepListItem *StepListItemModel) UnmarshalYAML(unmarshal func(interface{})
 	return nil
 }
 
+func (stepListStepItem *StepListStepItemModel) UnmarshalJSON(b []byte) error {
+	var raw map[string]stepmanModels.StepModel
+	if err := json.Unmarshal(b, &raw); err != nil {
+		return err
+	}
+
+	return stepListStepItem.fromRawStepListStepItem(raw)
+}
+
+func (stepListStepItem *StepListStepItemModel) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var raw map[string]stepmanModels.StepModel
+	if err := unmarshal(&raw); err != nil {
+		return err
+	}
+
+	return stepListStepItem.fromRawStepListStepItem(raw)
+}
+
+func (stepListStepItem *StepListStepItemModel) fromRawStepListStepItem(raw map[string]stepmanModels.StepModel) error {
+	var key string
+	for k := range raw {
+		key = k
+		break
+	}
+
+	// Only Steps are allowed
+	if key == StepListItemWithKey {
+		return errors.New("'with' group is not allowed in a step list")
+	}
+	if strings.HasPrefix(key, StepListItemStepBundleKeyPrefix) {
+		return errors.New("step bundle is not allowed in a step list")
+	}
+
+	*stepListStepItem = map[string]stepmanModels.StepModel{}
+	for k, v := range raw {
+		(*stepListStepItem)[k] = v
+	}
+
+	return nil
+}
+
 func (stepListStepItem *StepListStepItemModel) GetStepIDAndStep() (string, stepmanModels.StepModel, error) {
 	if stepListStepItem == nil {
 		return "", stepmanModels.StepModel{}, nil