diff --git a/tests/venv/binder-dir/binder/postBuild b/tests/venv/binder-dir/binder/postBuild
index 28b840f0..bfab97d3 100755
--- a/tests/venv/binder-dir/binder/postBuild
+++ b/tests/venv/binder-dir/binder/postBuild
@@ -1,2 +1,3 @@
 #!/bin/bash
+# FIXME: This doesn't work with ipyleaflet >= 0.19
 jupyter nbextension enable --py --sys-prefix ipyleaflet
diff --git a/tests/venv/binder-dir/binder/requirements.txt b/tests/venv/binder-dir/binder/requirements.txt
index 5a2f5096..42935ee7 100644
--- a/tests/venv/binder-dir/binder/requirements.txt
+++ b/tests/venv/binder-dir/binder/requirements.txt
@@ -1 +1 @@
-ipyleaflet
+ipyleaflet==0.18.2
diff --git a/tests/venv/start/postBuild/postBuild b/tests/venv/start/postBuild/postBuild
index dbf15529..da239e4e 100755
--- a/tests/venv/start/postBuild/postBuild
+++ b/tests/venv/start/postBuild/postBuild
@@ -3,4 +3,5 @@
 # this value should not be visible in `verify`
 export TEST_START_VAR="var is set by postBuild"
 
+# FIXME: This doesn't work with ipyleaflet >= 0.19
 jupyter nbextension enable --py --sys-prefix ipyleaflet
diff --git a/tests/venv/start/postBuild/requirements.txt b/tests/venv/start/postBuild/requirements.txt
index 5a2f5096..42935ee7 100644
--- a/tests/venv/start/postBuild/requirements.txt
+++ b/tests/venv/start/postBuild/requirements.txt
@@ -1 +1 @@
-ipyleaflet
+ipyleaflet==0.18.2