diff --git a/src/mbgl/particle/field/field_data_adapter.cpp b/src/mbgl/particle/field/field_data_adapter.cpp
index cb15372f0..2d04613cc 100644
--- a/src/mbgl/particle/field/field_data_adapter.cpp
+++ b/src/mbgl/particle/field/field_data_adapter.cpp
@@ -90,8 +90,9 @@ ParticleFieldAdapterResult ParticleFieldDataAdapter::decode(const ParticleFieldD
 }
 
 ParticleFieldAdapterResult ParticleFieldDataAdapter::decode(const ParticleFieldDescriptor& d, const std::vector<char>& bytes, uint64_t generation) {
-    if (!d.generation || !generation || d.generation != generation || d.layout != "interleaved-uv" || d.encoding != "float32-le" ||
-        (d.stride && d.stride != 2 * sizeof(float)) || !std::isfinite(d.noData))
+    if (d.layout != "interleaved-uv" || d.encoding != "float32-le")
+        return reject(ParticleFieldAdapterError::UnsupportedFormat, "legacy v1 only supports interleaved-uv float32-le");
+    if (!d.generation || !generation || d.generation != generation || (d.stride && d.stride != 2 * sizeof(float)) || !std::isfinite(d.noData))
         return reject(ParticleFieldAdapterError::InvalidDescriptor, "legacy v1 descriptor is invalid");
     ParticleFieldDescriptor normalized = d;
     normalized.vector = ParticleFieldPlaneDescriptor{.byteLength = d.byteLength, .encoding = d.encoding, .layout = d.layout, .noData = d.noData};
diff --git a/src/mbgl/particle/field/offline_fixture_particle_adapter.cpp b/src/mbgl/particle/field/offline_fixture_particle_adapter.cpp
index d6dcfcb61..e0efe12c4 100644
--- a/src/mbgl/particle/field/offline_fixture_particle_adapter.cpp
+++ b/src/mbgl/particle/field/offline_fixture_particle_adapter.cpp
@@ -158,6 +158,7 @@ ParticleFieldSnapshot OfflineFixtureParticleAdapter::load(const std::string& fix
     descriptor.fieldType = member(metadata, "fieldType").GetString();
     descriptor.displayDomain = member(metadata, "displayDomain").GetString();
     descriptor.generation = generation;
+    descriptor.validTime = member(metadata, "timeIndex").GetUint64() + 1;
     descriptor.width = grid["width"].GetUint();
     descriptor.height = grid["height"].GetUint();
     descriptor.west = bounds["west"].GetDouble();
diff --git a/test/style/source.test.cpp b/test/style/source.test.cpp
index c5e79f497..cac71a934 100644
--- a/test/style/source.test.cpp
+++ b/test/style/source.test.cpp
@@ -289,6 +289,9 @@ TEST(Source, ParticleFieldDataAdapterAcceptsNeutralDescriptor) {
     ASSERT_TRUE(result);
     ASSERT_TRUE(result.snapshot);
     EXPECT_EQ(result.snapshot->fieldID, descriptor.fieldID);
+    EXPECT_EQ(result.snapshot->vectorSemantics, particle::VectorSemantics::Velocity);
+    EXPECT_TRUE(result.snapshot->hasVector());
+    EXPECT_FALSE(result.snapshot->hasScalar());
     EXPECT_EQ(result.error, particle::ParticleFieldAdapterError::None);
 }