--- configure.ac
+++ configure.ac
@@ -1856,7 +1856,7 @@
     dri3_modifier_modules="xcb-dri3 >= $XCBDRI3_MODIFIERS_REQUIRED xcb-present >= $XCBPRESENT_MODIFIERS_REQUIRED"
     PKG_CHECK_MODULES([XCB_DRI3_MODIFIERS], [$dri3_modifier_modules], [have_dri3_modifiers=yes], [have_dri3_modifiers=no])

-    if test "x$have_dri3_modifiers" == xyes; then
+    if test "x$have_dri3_modifiers" = xyes; then
         DEFINES="$DEFINES -DHAVE_DRI3_MODIFIERS"
     fi
 fi