diff --git a/tests/unit/test_regressions.py b/tests/unit/test_regressions.py
index 749bf6307..a823d398e 100644
--- a/tests/unit/test_regressions.py
+++ b/tests/unit/test_regressions.py
@@ -1568,3 +1568,20 @@ def spam():
         )
         == snippet
     )
+
+
+def test_isort_shouldnt_add_extra_line_float_to_top_issue_1667():
+    assert isort.check_code(
+        """
+    import sys
+
+sys.path.insert(1, 'path/containing/something_else/..')
+
+import something_else  # isort:skip
+
+# Some constant
+SOME_CONSTANT = 4
+""",
+        show_diff=True,
+        float_to_top=True,
+    )