diff --git a/capa/features/extractors/cape/global_.py b/capa/features/extractors/cape/global_.py
index 83cb62728..62eeff204 100644
--- a/capa/features/extractors/cape/global_.py
+++ b/capa/features/extractors/cape/global_.py
@@ -12,14 +12,12 @@
 from capa.features.common import (
     OS,
     OS_ANY,
-    ARCH_ANY,
     OS_LINUX,
     ARCH_I386,
     FORMAT_PE,
     ARCH_AMD64,
     FORMAT_ELF,
     OS_WINDOWS,
-    FORMAT_UNKNOWN,
     Arch,
     Format,
     Feature,
diff --git a/capa/main.py b/capa/main.py
index fe6f78b2a..3a753cf8e 100644
--- a/capa/main.py
+++ b/capa/main.py
@@ -1007,13 +1007,13 @@ def collect_metadata(
     os_ = get_os(sample_path) if os_ == OS_AUTO else os_
 
     if isinstance(extractor, StaticFeatureExtractor):
-        flavor = rdoc.Flavor.STATIC
+        meta_class: type = rdoc.StaticMetadata
     elif isinstance(extractor, DynamicFeatureExtractor):
-        flavor = rdoc.Flavor.DYNAMIC
+        meta_class = rdoc.DynamicMetadata
     else:
         assert_never(extractor)
 
-    return rdoc.Metadata(
+    return meta_class(
         timestamp=datetime.datetime.now(),
         version=capa.version.__version__,
         argv=tuple(argv) if argv else None,
@@ -1023,7 +1023,6 @@ def collect_metadata(
             sha256=sha256,
             path=Path(sample_path).resolve().as_posix(),
         ),
-        flavor=flavor,
         analysis=get_sample_analysis(
             format_,
             arch,
diff --git a/capa/render/result_document.py b/capa/render/result_document.py
index 87790e53e..11066d0b9 100644
--- a/capa/render/result_document.py
+++ b/capa/render/result_document.py
@@ -136,6 +136,16 @@ class Metadata(Model):
     analysis: Analysis
 
 
+class StaticMetadata(Metadata):
+    flavor: Flavor = Flavor.STATIC
+    analysis: StaticAnalysis
+
+
+class DynamicMetadata(Metadata):
+    flavor: Flavor = Flavor.DYNAMIC
+    analysis: DynamicAnalysis
+
+
 class CompoundStatementType:
     AND = "and"
     OR = "or"
diff --git a/capa/render/verbose.py b/capa/render/verbose.py
index ae353855a..f8aa95b25 100644
--- a/capa/render/verbose.py
+++ b/capa/render/verbose.py
@@ -23,6 +23,7 @@
 See the License for the specific language governing permissions and limitations under the License.
 """
 import enum
+from typing import cast
 
 import tabulate
 
@@ -75,7 +76,7 @@ def format_address(address: frz.Address) -> str:
         raise ValueError("unexpected address type")
 
 
-def render_static_meta(ostream, meta: rd.Metadata):
+def render_static_meta(ostream, meta: rd.StaticMetadata):
     """
     like:
 
@@ -96,7 +97,6 @@ def render_static_meta(ostream, meta: rd.Metadata):
         total feature count  1918
     """
 
-    assert isinstance(meta.analysis, rd.StaticAnalysis)
     rows = [
         ("md5", meta.sample.md5),
         ("sha1", meta.sample.sha1),
@@ -122,7 +122,7 @@ def render_static_meta(ostream, meta: rd.Metadata):
     ostream.writeln(tabulate.tabulate(rows, tablefmt="plain"))
 
 
-def render_dynamic_meta(ostream, meta: rd.Metadata):
+def render_dynamic_meta(ostream, meta: rd.DynamicMetadata):
     """
     like:
 
@@ -141,7 +141,6 @@ def render_dynamic_meta(ostream, meta: rd.Metadata):
         total feature count  1918
     """
 
-    assert isinstance(meta.analysis, rd.DynamicAnalysis)
     rows = [
         ("md5", meta.sample.md5),
         ("sha1", meta.sample.sha1),
@@ -166,10 +165,10 @@ def render_dynamic_meta(ostream, meta: rd.Metadata):
 
 
 def render_meta(osstream, doc: rd.ResultDocument):
-    if isinstance(doc.meta.analysis, rd.StaticAnalysis):
-        render_static_meta(osstream, doc.meta)
-    elif isinstance(doc.meta.analysis, rd.DynamicAnalysis):
-        render_dynamic_meta(osstream, doc.meta)
+    if doc.meta.flavor is rd.Flavor.STATIC:
+        render_static_meta(osstream, cast(rd.StaticMetadata, doc.meta))
+    elif doc.meta.flavor is rd.Flavor.DYNAMIC:
+        render_dynamic_meta(osstream, cast(rd.DynamicMetadata, doc.meta))
     else:
         raise ValueError("invalid meta analysis")
 
diff --git a/scripts/profile-time.py b/scripts/profile-time.py
index db9a99fe3..9acd60ff4 100644
--- a/scripts/profile-time.py
+++ b/scripts/profile-time.py
@@ -54,7 +54,6 @@
 import capa.features
 import capa.features.common
 import capa.features.freeze
-from capa.features.extractors.base_extractor import FeatureExtractor, StaticFeatureExtractor
 
 logger = logging.getLogger("capa.profile")
 
diff --git a/tests/test_dynamic_freeze.py b/tests/test_dynamic_freeze.py
new file mode 100644
index 000000000..e69de29bb