diff --git a/tests/data/large-write-file.txt b/tests/data/large-write-file.txt
deleted file mode 100644
index d4c5011..0000000
Binary files a/tests/data/large-write-file.txt and /dev/null differ
diff --git a/tests/unit/file.c b/tests/unit/file.c
index a99c044..1aec04f 100644
--- a/tests/unit/file.c
+++ b/tests/unit/file.c
@@ -152,6 +152,11 @@ COSMS_CORE_TEST_TEST(file_size,
                     cosms_core_test_sub_test_error = "result does not match expected result";
                 }
             }
+
+            error = cosms_core_file_close(&file);
+            if (error != COSMS_CORE_FILE_OK) {
+                cosms_core_test_sub_test_error = cosms_core_file_error_string(error);
+            }
         }
     )
 
@@ -170,6 +175,11 @@ COSMS_CORE_TEST_TEST(file_size,
                     cosms_core_test_sub_test_error = "result does not match expected result";
                 }
             }
+
+            error = cosms_core_file_close(&file);
+            if (error != COSMS_CORE_FILE_OK) {
+                cosms_core_test_sub_test_error = cosms_core_file_error_string(error);
+            }
         }
     )