diff --git a/src/specify_cli/workflows/catalog.py b/src/specify_cli/workflows/catalog.py
index 61f490631c..f944f95bfd 100644
--- a/src/specify_cli/workflows/catalog.py
+++ b/src/specify_cli/workflows/catalog.py
@@ -784,12 +784,17 @@ def remove_catalog(self, index: int) -> str:
             raise WorkflowValidationError("No catalog config file found.")
 
         try:
-            data = yaml.safe_load(config_path.read_text(encoding="utf-8")) or {}
+            data = yaml.safe_load(config_path.read_text(encoding="utf-8"))
         except (yaml.YAMLError, OSError, UnicodeDecodeError) as exc:
             raise WorkflowValidationError(
                 f"Catalog config file is unreadable or malformed: {exc}"
             ) from exc
-        if not isinstance(data, dict):
+        # Do NOT coerce with ``or {}`` here: that also turns a FALSY non-mapping
+        # (top-level ``[]``, ``false``, ``0``, ``''``) into ``{}`` and silently
+        # swallows it, matching _load_catalog_config's guard above.
+        if data is None:
+            data = {}
+        elif not isinstance(data, dict):
             raise WorkflowValidationError(
                 "Catalog config file is corrupted (expected a mapping)."
             )
@@ -1394,11 +1399,16 @@ def add_catalog(self, url: str, name: str | None = None) -> None:
         data: dict[str, Any] = {"catalogs": []}
         if config_path.exists():
             try:
-                raw = yaml.safe_load(config_path.read_text(encoding="utf-8")) or {}
+                raw = yaml.safe_load(config_path.read_text(encoding="utf-8"))
             except (yaml.YAMLError, OSError, UnicodeDecodeError) as exc:
                 raise StepValidationError(
                     f"Catalog config file is unreadable or malformed: {exc}"
                 ) from exc
+            # Do NOT coerce with ``or {}`` here: that also turns a FALSY
+            # non-mapping (top-level ``[]``, ``false``, ``0``, ``''``) into
+            # ``{}`` and silently swallows it.
+            if raw is None:
+                raw = {"catalogs": []}
             if not isinstance(raw, dict):
                 raise StepValidationError(
                     "Catalog config file is corrupted (expected a mapping)."
@@ -1463,12 +1473,17 @@ def remove_catalog(self, index: int) -> str:
             raise StepValidationError("No step catalog config file found.")
 
         try:
-            data = yaml.safe_load(config_path.read_text(encoding="utf-8")) or {}
+            data = yaml.safe_load(config_path.read_text(encoding="utf-8"))
         except (yaml.YAMLError, OSError, UnicodeDecodeError) as exc:
             raise StepValidationError(
                 f"Catalog config file is unreadable or malformed: {exc}"
             ) from exc
-        if not isinstance(data, dict):
+        # Do NOT coerce with ``or {}`` here: that also turns a FALSY non-mapping
+        # (top-level ``[]``, ``false``, ``0``, ``''``) into ``{}`` and silently
+        # swallows it.
+        if data is None:
+            data = {}
+        elif not isinstance(data, dict):
             raise StepValidationError(
                 "Catalog config file is corrupted (expected a mapping)."
             )
diff --git a/tests/test_workflows.py b/tests/test_workflows.py
index d599f3c6a4..9e9a896438 100644
--- a/tests/test_workflows.py
+++ b/tests/test_workflows.py
@@ -8453,6 +8453,20 @@ def test_remove_catalog_malformed_yaml_raises(self, project_dir):
         with pytest.raises(WorkflowValidationError, match="unreadable or malformed"):
             catalog.remove_catalog(0)
 
+    @pytest.mark.parametrize("body", ["[]\n", "false\n", "0\n", "''\n"])
+    def test_remove_catalog_rejects_falsy_non_mapping_config(self, project_dir, body):
+        """A FALSY non-mapping top-level config ([], false, 0, '') must raise
+        'corrupted (expected a mapping)', not be silently coerced to {} by
+        ``or {}`` and then fail as a misleading 'out of range' error."""
+        from specify_cli.workflows.catalog import WorkflowCatalog, WorkflowValidationError
+
+        config_path = project_dir / ".specify" / "workflow-catalogs.yml"
+        config_path.write_text(body, encoding="utf-8")
+
+        catalog = WorkflowCatalog(project_dir)
+        with pytest.raises(WorkflowValidationError, match="expected a mapping"):
+            catalog.remove_catalog(0)
+
     def test_add_catalog_wraps_write_oserror(self, project_dir, monkeypatch):
         """An OSError on write must be wrapped as WorkflowValidationError."""
         from specify_cli.workflows.catalog import WorkflowCatalog, WorkflowValidationError
@@ -9099,6 +9113,21 @@ def test_add_catalog_duplicate_rejected(self, project_dir):
         with pytest.raises(StepValidationError, match="already configured"):
             catalog.add_catalog("https://example.com/steps.json")
 
+    @pytest.mark.parametrize("body", ["[]\n", "false\n", "0\n", "''\n"])
+    def test_add_catalog_rejects_falsy_non_mapping_config(self, project_dir, body):
+        """A FALSY non-mapping top-level config ([], false, 0, '') must raise
+        'corrupted (expected a mapping)', not be silently coerced to {} by
+        ``or {}`` — matching the empty-document case above, which correctly
+        treats only a real absence of a document (None) as empty."""
+        from specify_cli.workflows.catalog import StepCatalog, StepValidationError
+
+        config_path = project_dir / ".specify" / "step-catalogs.yml"
+        config_path.write_text(body, encoding="utf-8")
+
+        catalog = StepCatalog(project_dir)
+        with pytest.raises(StepValidationError, match="expected a mapping"):
+            catalog.add_catalog("https://example.com/steps.json")
+
     def test_remove_catalog(self, project_dir):
         from specify_cli.workflows.catalog import StepCatalog
 
@@ -9122,6 +9151,20 @@ def test_remove_catalog_invalid_index(self, project_dir):
         with pytest.raises(StepValidationError, match="out of range"):
             catalog.remove_catalog(5)
 
+    @pytest.mark.parametrize("body", ["[]\n", "false\n", "0\n", "''\n"])
+    def test_remove_catalog_rejects_falsy_non_mapping_config(self, project_dir, body):
+        """A FALSY non-mapping top-level config ([], false, 0, '') must raise
+        'corrupted (expected a mapping)', not be silently coerced to {} by
+        ``or {}`` and then fail as a misleading 'out of range' error."""
+        from specify_cli.workflows.catalog import StepCatalog, StepValidationError
+
+        config_path = project_dir / ".specify" / "step-catalogs.yml"
+        config_path.write_text(body, encoding="utf-8")
+
+        catalog = StepCatalog(project_dir)
+        with pytest.raises(StepValidationError, match="expected a mapping"):
+            catalog.remove_catalog(0)
+
     def test_remove_catalog_no_config(self, project_dir):
         from specify_cli.workflows.catalog import StepCatalog, StepValidationError