diff --git a/debian/rules b/debian/rules
index 70cd277..d0a8918 100755
--- a/debian/rules
+++ b/debian/rules
@@ -30,6 +30,9 @@
 DEB_UPSTREAM_TARBALL_EXTENSION = tar.bz2
 DEB_UPSTREAM_TARBALL_MD5 = 360a99ab3ce66c035b19679deb34bad4
 
+# Catch GTK miscompilations. See http://bugs.sugarlabs.org/ticket/1899
+CFLAGS += -W -Werror=implicit-function-declaration
+
 # Register icons for optional caching
 binary-install/$(pkg)::
 	dh_icons -p$(cdbs_curpkg)