diff --git a/configure.in b/configure.in
index 59e62414f6..1d8fed5810 100644
--- a/configure.in
+++ b/configure.in
@@ -584,7 +584,7 @@ if test "$GCC:${warnflags+set}:no" = yes::no; then
     warnflags=
 fi
 if test "$GCC" = yes; then
-    test "${debugflags+set}" || {RUBY_TRY_CFLAGS(-ggdb3, [debugflags=-ggdb])}
+    test "${debugflags+set}" || {RUBY_TRY_CFLAGS(-ggdb3, [debugflags=-ggdb3])}
     test "${debugflags+set}" || {RUBY_TRY_CFLAGS(-ggdb, [debugflags=-ggdb])}
     test "${debugflags+set}" || {RUBY_TRY_CFLAGS(-g3, [debugflags=-g3])}