diff --git a/requirements/core.txt b/requirements/core.txt
index c3f5775d7e..c7adb469cc 100644
--- a/requirements/core.txt
+++ b/requirements/core.txt
@@ -6,9 +6,9 @@
 cartopy>=0.12
 #conda: proj4<6
 cf-units>=2
-cftime
+cftime<1.1
 dask[array]>=2  #conda: dask>=2
-matplotlib
+matplotlib<=3.1
 netcdf4
-numpy>=1.14
+numpy<=1.17
 scipy
diff --git a/requirements/test.txt b/requirements/test.txt
index 89358f7f76..89cd043fa1 100644
--- a/requirements/test.txt
+++ b/requirements/test.txt
@@ -3,7 +3,8 @@
 
 black==19.10b0  #conda: black=19.10b0
 filelock
-imagehash>=4.0
+pillow<7
+imagehash
 nose
 pre-commit
 requests