diff --git a/lib/spack/spack/database.py b/lib/spack/spack/database.py
index e2f9e57e82..3c7dff96db 100644
--- a/lib/spack/spack/database.py
+++ b/lib/spack/spack/database.py
@@ -25,6 +25,7 @@
 import socket
 import sys
 import time
+from json import JSONDecoder
 from typing import (
     Any,
     Callable,
@@ -818,7 +819,8 @@ def _read_from_file(self, filename):
         """
         try:
             with open(filename, "r") as f:
-                fdata = sjson.load(f)
+                # In the future we may use a stream of JSON objects, hence `raw_decode` for compat.
+                fdata, _ = JSONDecoder().raw_decode(f.read())
         except Exception as e:
             raise CorruptDatabaseError("error parsing database:", str(e)) from e
 
@@ -833,27 +835,24 @@ def check(cond, msg):
 
         # High-level file checks
         db = fdata["database"]
-        check("installs" in db, "no 'installs' in JSON DB.")
         check("version" in db, "no 'version' in JSON DB.")
 
-        installs = db["installs"]
-
         # TODO: better version checking semantics.
         version = vn.Version(db["version"])
         if version > _DB_VERSION:
             raise InvalidDatabaseVersionError(self, _DB_VERSION, version)
-        elif version < _DB_VERSION:
-            if not any(old == version and new == _DB_VERSION for old, new in _SKIP_REINDEX):
-                tty.warn(
-                    "Spack database version changed from %s to %s. Upgrading."
-                    % (version, _DB_VERSION)
-                )
+        elif version < _DB_VERSION and not any(
+            old == version and new == _DB_VERSION for old, new in _SKIP_REINDEX
+        ):
+            tty.warn(f"Spack database version changed from {version} to {_DB_VERSION}. Upgrading.")
 
-                self.reindex(spack.store.STORE.layout)
-                installs = dict(
-                    (k, v.to_dict(include_fields=self._record_fields))
-                    for k, v in self._data.items()
-                )
+            self.reindex(spack.store.STORE.layout)
+            installs = dict(
+                (k, v.to_dict(include_fields=self._record_fields)) for k, v in self._data.items()
+            )
+        else:
+            check("installs" in db, "no 'installs' in JSON DB.")
+            installs = db["installs"]
 
         spec_reader = reader(version)
 
diff --git a/lib/spack/spack/test/database.py b/lib/spack/spack/test/database.py
index 0b611e93e3..b981191676 100644
--- a/lib/spack/spack/test/database.py
+++ b/lib/spack/spack/test/database.py
@@ -1106,3 +1106,31 @@ def test_database_construction_doesnt_use_globals(tmpdir, config, nullify_global
     lock_cfg = lock_cfg or spack.database.lock_configuration(config)
     db = spack.database.Database(str(tmpdir), lock_cfg=lock_cfg)
     assert os.path.exists(db.database_directory)
+
+
+def test_database_read_works_with_trailing_data(tmp_path, default_mock_concretization):
+    # Populate a database
+    root = str(tmp_path)
+    db = spack.database.Database(root)
+    spec = default_mock_concretization("a")
+    db.add(spec, directory_layout=None)
+    specs_in_db = db.query_local()
+    assert spec in specs_in_db
+
+    # Append anything to the end of the database file
+    with open(db._index_path, "a") as f:
+        f.write(json.dumps({"hello": "world"}))
+
+    # Read the database and check that it ignores the trailing data
+    assert spack.database.Database(root).query_local() == specs_in_db
+
+
+def test_database_errors_with_just_a_version_key(tmp_path):
+    root = str(tmp_path)
+    db = spack.database.Database(root)
+    next_version = f"{spack.database._DB_VERSION}.next"
+    with open(db._index_path, "w") as f:
+        f.write(json.dumps({"database": {"version": next_version}}))
+
+    with pytest.raises(spack.database.InvalidDatabaseVersionError):
+        spack.database.Database(root).query_local()