diff --git a/lib/matplotlib/backends/backend_qt4agg.py b/lib/matplotlib/backends/backend_qt4agg.py
index 65785bbd32bb..8f4e265ac424 100644
--- a/lib/matplotlib/backends/backend_qt4agg.py
+++ b/lib/matplotlib/backends/backend_qt4agg.py
@@ -8,4 +8,4 @@
 
 @_BackendQT5Agg.export
 class _BackendQT4Agg(_BackendQT5Agg):
-    pass
+    required_interactive_framework = "qt4"
diff --git a/lib/matplotlib/backends/backend_qt4cairo.py b/lib/matplotlib/backends/backend_qt4cairo.py
index f94851da382d..94d703afa4ea 100644
--- a/lib/matplotlib/backends/backend_qt4cairo.py
+++ b/lib/matplotlib/backends/backend_qt4cairo.py
@@ -3,4 +3,4 @@
 
 @_BackendQT5Cairo.export
 class _BackendQT4Cairo(_BackendQT5Cairo):
-    pass
+    required_interactive_framework = "qt4"