diff --git a/gcc/common/config/avr/avr-common.cc b/gcc/common/config/avr/avr-common.cc
index 2f874c5b81c7..cdbe58ad4a89 100644
--- a/gcc/common/config/avr/avr-common.cc
+++ b/gcc/common/config/avr/avr-common.cc
@@ -29,6 +29,13 @@
 /* Implement TARGET_OPTION_OPTIMIZATION_TABLE.  */
 static const struct default_options avr_option_optimization_table[] =
   {
+    // The lookup table from tree-swicth-conversion.cc lives in .rodata
+    // and hence consumes RAM on almost all devices.  As PR49857 has
+    // been rejected several times for non-technical reasons, just
+    // disable -ftree-switch-conversion by default.  But even with PR49857
+    // in place there remains PR81540, which cannot be filtered out since
+    // the pass has no way to hook in.
+    { OPT_LEVELS_ALL, OPT_ftree_switch_conversion, NULL, 0 },
     // The only effect of -fcaller-saves might be that it triggers
     // a frame without need when it tries to be smart around calls.
     { OPT_LEVELS_ALL, OPT_fcaller_saves, NULL, 0 },