diff --git a/configure.ac b/configure.ac
index 8d211bdcd..96767b74f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -86,7 +86,7 @@ dnl Check that we meet the  dependencies
 dnl ==============================================
 
 GLIB_REQUIRED_VERSION=2.44.0
-GTK_REQUIRED_VERSION=3.21.4
+GTK_REQUIRED_VERSION=3.21.5
 PA_REQUIRED_VERSION=2.0
 CANBERRA_REQUIRED_VERSION=0.13
 GDKPIXBUF_REQUIRED_VERSION=2.23.0