diff --git a/REQUIREMENTS.txt b/REQUIREMENTS.txt
index e645accc..25bbdf92 100644
--- a/REQUIREMENTS.txt
+++ b/REQUIREMENTS.txt
@@ -22,8 +22,9 @@ scipy
 showit >= 1.1.4
 slicedimage==4.1.1
 sympy ~= 1.5.0
+urllib3 <1.27, >=1.25.4
 tqdm
 trackpy
 validators
 xarray >= 0.14.1
-ipywidgets
\ No newline at end of file
+ipywidgets