diff --git a/gnu/dist/toolchain/gdb/gdbserver/configure b/gnu/dist/toolchain/gdb/gdbserver/configure
index a160c85c1cdc..62c305bfe766 100644
--- a/gnu/dist/toolchain/gdb/gdbserver/configure
+++ b/gnu/dist/toolchain/gdb/gdbserver/configure
@@ -561,7 +561,7 @@ esac
 
 
 # Make sure we can run config.sub.
-if $ac_config_sub sun4 >/dev/null 2>&1; then :
+if ${CONFIG_SHELL-/bin/sh} $ac_config_sub sun4 >/dev/null 2>&1; then :
 else { echo "configure: error: can not run $ac_config_sub" 1>&2; exit 1; }
 fi
 
@@ -580,7 +580,7 @@ NONE)
   esac ;;
 esac
 
-host=`$ac_config_sub $host_alias`
+host=`${CONFIG_SHELL-/bin/sh} $ac_config_sub $host_alias`
 host_cpu=`echo $host | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\1/'`
 host_vendor=`echo $host | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\2/'`
 host_os=`echo $host | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\3/'`
@@ -598,7 +598,7 @@ NONE)
   esac ;;
 esac
 
-target=`$ac_config_sub $target_alias`
+target=`${CONFIG_SHELL-/bin/sh} $ac_config_sub $target_alias`
 target_cpu=`echo $target | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\1/'`
 target_vendor=`echo $target | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\2/'`
 target_os=`echo $target | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\3/'`
@@ -616,7 +616,7 @@ NONE)
   esac ;;
 esac
 
-build=`$ac_config_sub $build_alias`
+build=`${CONFIG_SHELL-/bin/sh} $ac_config_sub $build_alias`
 build_cpu=`echo $build | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\1/'`
 build_vendor=`echo $build | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\2/'`
 build_os=`echo $build | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\3/'`