diff --git a/bench_conprod.py b/bench_conprod.py
index 60a988901355f1f23c5ba6d9807147eb7462f0e3..19a376961095b68bbbc089d80f38c47e9ea0415f 100644
--- a/bench_conprod.py
+++ b/bench_conprod.py
@@ -82,7 +82,7 @@ class Benchmark_ConProd( Benchmark ):
                         print(output)
                         return False
 
-                    if "ERROR: ld.so" in p.stderr:
+                    if "ERROR: ld.so" in output:
                         print("\nPreloading of", t[1], "failed for", tname, ".\n Aborting Benchmark.")
                         return False
 
diff --git a/bench_loop.py b/bench_loop.py
index f5606c6404a758208d669bdba8eb68314b388f7b..e5de2b933269d4cb72986edba00738edf5ee0b91 100644
--- a/bench_loop.py
+++ b/bench_loop.py
@@ -83,7 +83,7 @@ class Benchmark_Loop( Benchmark ):
                         print(p.stdout)
                         return False
 
-                    if "ERROR: ld.so" in p.stderr:
+                    if "ERROR: ld.so" in output:
                         print("\nPreloading of", t[1], "failed for", tname, ".\n Aborting Benchmark.")
                         return False