diff --git a/testsuite/tools/test-simplify.in b/testsuite/tools/test-simplify.in
index 2de4366b16..6b4f2e8131 100755
--- a/testsuite/tools/test-simplify.in
+++ b/testsuite/tools/test-simplify.in
@@ -1,4 +1,4 @@
-#! /bin/sh
+#! /bin/bash
 
 GTK_BUILDER_TOOL=${GTK_BUILDER_TOOL:-gtk-builder-tool}
 TEST_DATA_DIR=${TEST_DATA_DIR:-./simplify}