diff --git a/picard/coverart/providers/caa.py b/picard/coverart/providers/caa.py
index 4dcf521f5..53443f64e 100644
--- a/picard/coverart/providers/caa.py
+++ b/picard/coverart/providers/caa.py
@@ -217,7 +217,9 @@ class CAATypesSelectorDialog(PicardDialog):
             types_exclude = []
 
         self.setWindowTitle(_("Cover art types"))
+        self.setWindowModality(QtCore.Qt.WindowModal)
         self.layout = QtWidgets.QVBoxLayout(self)
+        self.layout.setSizeConstraint(QtWidgets.QLayout.SetFixedSize)
 
         # Create list boxes for dialog
         self.list_include = ListBox()
diff --git a/picard/ui/options/interface.py b/picard/ui/options/interface.py
index 2883b6eb7..7e5805a88 100644
--- a/picard/ui/options/interface.py
+++ b/picard/ui/options/interface.py
@@ -288,6 +288,7 @@ class ToolbarListItem(QtWidgets.QListWidgetItem):
 class AddActionDialog(PicardDialog):
     def __init__(self, action_list, *args, **kwargs):
         super().__init__(*args, **kwargs)
+        self.setWindowModality(QtCore.Qt.WindowModal)
 
         layout = QtWidgets.QVBoxLayout(self)