diff --git a/configure.ac b/configure.ac
index 98bc48854f..55b2d93eae 100644
--- a/configure.ac
+++ b/configure.ac
@@ -276,7 +276,8 @@ AS_IF([test "x$cross_compiling" = xno], [
     AC_PATH_PROG([MJIT_CC], ${MJIT_CC})
 
     # if $CC is in /usr/lib/ccache/$CC, search original $CC (disable ccache)
-    AS_IF([echo $MJIT_CC | grep ^/usr/lib/ccache > /dev/null], [
+    AS_IF([echo $RUBY_DEBUG | grep ci > /dev/null &&
+           echo $MJIT_CC | grep ^/usr/lib/ccache > /dev/null], [
            PATH=`echo $PATH | sed "s/\/usr\/lib\/ccache://"` MJIT_CC=`which $CC`])
 
     AS_CASE([$target_os],