diff --git a/infer/src/bufferoverrun/bufferOverrunModels.ml b/infer/src/bufferoverrun/bufferOverrunModels.ml
index 4326d2793..e25b69099 100644
--- a/infer/src/bufferoverrun/bufferOverrunModels.ml
+++ b/infer/src/bufferoverrun/bufferOverrunModels.ml
@@ -1713,6 +1713,9 @@ module Call = struct
         $--> NSCollection.new_collection_by_add_all
       ; +PatternMatch.ObjectiveC.implements "NSEnumerator"
         &:: "nextObject" <>$ capt_exp $--> NSCollection.next_object
+      ; +PatternMatch.ObjectiveC.implements "NSFileManager"
+        &:: "contentsOfDirectoryAtURL:includingPropertiesForKeys:options:error:"
+        &--> NSCollection.new_collection
       ; +PatternMatch.ObjectiveC.implements "NSKeyedUnarchiver"
         &:: "decodeObjectForKey:" $ capt_var_exn $+...$--> NSCollection.get_any_index
       ; +PatternMatch.ObjectiveC.implements "NSMutableArray"
diff --git a/infer/tests/codetoanalyze/objc/performance/NSFileManager.m b/infer/tests/codetoanalyze/objc/performance/NSFileManager.m
new file mode 100644
index 000000000..d9011b107
--- /dev/null
+++ b/infer/tests/codetoanalyze/objc/performance/NSFileManager.m
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+#import <Foundation/Foundation.h>
+
+/* We model the file lookup as returning a constant-length collection
+ * (T77961166). */
+void contents_of_directory_at_url_constant(NSFileManager* file_manager,
+                                           NSURL* url,
+                                           NSArray* keys) {
+  NSArray* array = [file_manager contentsOfDirectoryAtURL:url
+                               includingPropertiesForKeys:keys
+                                                  options:0
+                                                    error:nil];
+  for (int i = 0; i < array.count; i++) {
+  }
+}
diff --git a/infer/tests/codetoanalyze/objc/performance/cost-issues.exp b/infer/tests/codetoanalyze/objc/performance/cost-issues.exp
index cdf263eaf..f01847a57 100644
--- a/infer/tests/codetoanalyze/objc/performance/cost-issues.exp
+++ b/infer/tests/codetoanalyze/objc/performance/cost-issues.exp
@@ -43,6 +43,7 @@ codetoanalyze/objc/performance/NSDictionary.m, nsdictionary_find_key_constant, 1
 codetoanalyze/objc/performance/NSDictionary.m, nsdictionary_init_dictionary_constant, 3,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSDictionary.m, nsdictionary_init_literal_constant, 45,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSDictionary.m, nsdictionary_init_with_dictionary_linear, 7 + 3 ⋅ dict->elements.length.ub + 4 ⋅ (dict->elements.length.ub + 1),  OnUIThread:false, [{dict->elements.length.ub + 1},Loop,{dict->elements.length.ub},Loop]
+codetoanalyze/objc/performance/NSFileManager.m, contents_of_directory_at_url_constant, 11,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSInteger.m, nsinteger_value_linear, 3 + 3 ⋅ integer + 2 ⋅ (1+max(0, integer)),  OnUIThread:false, [{1+max(0, integer)},Loop,{integer},Loop]
 codetoanalyze/objc/performance/NSInteger.m, nsnumber_number_with_int_integer_value_constant, 34,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSKeyedUnarchiver.m, decode_object_for_key_linear, 9 + 3 ⋅ keyed_unarchiver->elements[*].ub + 2 ⋅ (1+max(0, keyed_unarchiver->elements[*].ub)),  OnUIThread:false, [{1+max(0, keyed_unarchiver->elements[*].ub)},Loop,{keyed_unarchiver->elements[*].ub},Loop]
diff --git a/infer/tests/codetoanalyze/objc/performance/issues.exp b/infer/tests/codetoanalyze/objc/performance/issues.exp
index 78f9630d3..bb7fa4dd9 100644
--- a/infer/tests/codetoanalyze/objc/performance/issues.exp
+++ b/infer/tests/codetoanalyze/objc/performance/issues.exp
@@ -1,5 +1,6 @@
 codetoanalyze/objc/performance/NSArray.m, nsarray_empty_array_constant, 3, CONDITION_ALWAYS_FALSE, no_bucket, WARNING, [Here]
 codetoanalyze/objc/performance/NSArray.m, nsarray_init_constant, 3, CONDITION_ALWAYS_FALSE, no_bucket, WARNING, [Here]
+codetoanalyze/objc/performance/NSFileManager.m, contents_of_directory_at_url_constant, 7, CONDITION_ALWAYS_FALSE, no_bucket, WARNING, [Here]
 codetoanalyze/objc/performance/NSMutableArray.m, nsarray_new_constant, 2, CONDITION_ALWAYS_FALSE, no_bucket, WARNING, [Here]
 codetoanalyze/objc/performance/NSMutableArray.m, nsmarray_remove_constant, 6, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Length trace>,Array declaration,Through,Through,Through,Through,Array access: Offset: 0 Size: 0]
 codetoanalyze/objc/performance/NSMutableArray.m, nsmarray_remove_in_loop_constant, 6, BUFFER_OVERRUN_L3, no_bucket, ERROR, [<Offset trace>,Set array size,<Length trace>,Assignment,Set array size,Array access: Offset: [0, 9] Size: [1, 10]]