diff --git a/libstdc++-v3/testsuite/lib/dg-options.exp b/libstdc++-v3/testsuite/lib/dg-options.exp
index 73c1552e682..15e34f8a646 100644
--- a/libstdc++-v3/testsuite/lib/dg-options.exp
+++ b/libstdc++-v3/testsuite/lib/dg-options.exp
@@ -269,8 +269,10 @@ proc dg-require-target-fs-lwt { args } {
 }
 
 proc add_options_for_no_pch { flags } {
+    # Remove any inclusion of bits/stdc++.h from the options.
+    regsub -all -- "-include bits/stdc...h" $flags "" flags
     # This forces any generated and possibly included PCH to be invalid.
-    return "-D__GLIBCXX__=99999999"
+    return "$flags -D__GLIBCXX__=99999999"
 }
 
 # Add to FLAGS all the target-specific flags needed for networking.