diff --git a/mps/test/conerr/15.c b/mps/test/conerr/15.c
index c4114d5b995..4bd52651fa3 100644
--- a/mps/test/conerr/15.c
+++ b/mps/test/conerr/15.c
@@ -16,13 +16,6 @@ static void test(void)
 {
  mps_arena_t arena;
  mps_pool_t pool = (mps_pool_t)1;
- size_t extendBy;
- size_t avgSize;
- size_t maxSize;
-
- extendBy = (size_t) 4096;
- avgSize  = (size_t) 32;
- maxSize  = (size_t) 65536;
 
  cdie(mps_arena_create(&arena, mps_arena_class_vm(), mmqaArenaSIZE), "create arena");
 
diff --git a/mps/test/conerr/19.c b/mps/test/conerr/19.c
index 3c8211c23dd..430d013c7f9 100644
--- a/mps/test/conerr/19.c
+++ b/mps/test/conerr/19.c
@@ -16,16 +16,9 @@ static void test(void)
 {
  mps_arena_t arena;
  mps_pool_t pool = (mps_pool_t)1;
- size_t extendBy;
- size_t avgSize;
- size_t maxSize;
 
  mps_addr_t obj;
 
- extendBy = (size_t) 4096;
- avgSize  = (size_t) 32;
- maxSize  = (size_t) 65536;
-
  cdie(mps_arena_create(&arena, mps_arena_class_vm(), mmqaArenaSIZE), "create arena");
 
 /*
diff --git a/mps/test/conerr/25.c b/mps/test/conerr/25.c
index 480b382b8f4..35e4c5c03c7 100644
--- a/mps/test/conerr/25.c
+++ b/mps/test/conerr/25.c
@@ -31,7 +31,7 @@ static void test(void)
  cdie(mps_ap_create(&ap, pool), "create ap");
 
  cdie(mps_reserve(&obj, ap, 152), "reserve");
- mps_commit(ap, &obj, 152);
+ (void)mps_commit(ap, &obj, 152);
 
  mps_free(pool, obj, 152);
  comment("Freed.");
diff --git a/mps/test/conerr/43.c b/mps/test/conerr/43.c
index 1532e2f9a88..ce29bc3cb69 100644
--- a/mps/test/conerr/43.c
+++ b/mps/test/conerr/43.c
@@ -19,7 +19,6 @@ static void test(void)
 {
  mps_arena_t arena;
  mps_root_t root = (mps_root_t)1;
- mps_addr_t roottable[10];
 
  cdie(mps_arena_create(&arena, mps_arena_class_vm(), mmqaArenaSIZE), "create arena");
 
diff --git a/mps/test/conerr/5.c b/mps/test/conerr/5.c
index 09a1893f31d..f6559c4824e 100644
--- a/mps/test/conerr/5.c
+++ b/mps/test/conerr/5.c
@@ -18,7 +18,6 @@ static void test(void)
 {
  mps_arena_t arena;
  mps_fmt_t format;
- mps_fmt_A_s fmtA;
 
  cdie(mps_arena_create(&arena, mps_arena_class_vm(), mmqaArenaSIZE), "create arena");