diff --git a/src/animation/offline/animation_builder.cc b/src/animation/offline/animation_builder.cc
index 5fd3d520d..51e44b72b 100644
--- a/src/animation/offline/animation_builder.cc
+++ b/src/animation/offline/animation_builder.cc
@@ -196,10 +196,9 @@ void CopyTimePoints(const span<const float>& _times, float _inv_duration,
 }
 
 uint16_t TimePointToIndex(const span<const float>& _timepoints, float _time) {
-  const float* found = std::find(_timepoints.begin(), _timepoints.end(), _time);
-  if (found == _timepoints.end()) {
-    assert(found != _timepoints.end());
-  }
+  const float* found =
+      std::lower_bound(_timepoints.begin(), _timepoints.end(), _time);
+  assert(found != _timepoints.end() && *found == _time);
   const ptrdiff_t distance = found - _timepoints.begin();
   assert(distance >= 0 && distance < std::numeric_limits<uint16_t>::max());
   return static_cast<uint16_t>(distance);
diff --git a/test/animation/offline/animation_builder_tests.cc b/test/animation/offline/animation_builder_tests.cc
index 5cf3bde7f..040b0d42f 100644
--- a/test/animation/offline/animation_builder_tests.cc
+++ b/test/animation/offline/animation_builder_tests.cc
@@ -402,9 +402,17 @@ TEST(ManyKeys, SamplingJob) {
     raw_animation.tracks[0].translations.push_back(key2);
   }
 
-  // Track 1 has no key
+  // Track 1 has lots of keys
+  {
+    for (size_t i = 0; i < kMaxKey; ++i) {
+      const RawAnimation::TranslationKey key = {i * 1.f / kMaxKey,
+                                                ozz::math::Float3(0, 0, 0)};
+      raw_animation.tracks[1].translations.push_back(key);
+    }
+  }
 
-  // Track 2 has lots of keys
+  // Track 2 has lots of keys (same timepoints as track 1 as number of
+  // trackpoints is limited)
   {
     for (size_t i = 0; i < kMaxKey; ++i) {
       const RawAnimation::TranslationKey key = {