diff --git a/regressions/ck_ht/benchmark/Makefile b/regressions/ck_ht/benchmark/Makefile
index 8e21d5b..fa31274 100644
--- a/regressions/ck_ht/benchmark/Makefile
+++ b/regressions/ck_ht/benchmark/Makefile
@@ -1,12 +1,18 @@
 .PHONY: clean distribution
 
-OBJECTS=serial parallel_bytestring parallel_direct
+OBJECTS=serial serial.delete parallel_bytestring parallel_bytestring.delete parallel_direct
 
 all: $(OBJECTS)
 
 serial: serial.c ../../../include/ck_ht.h ../../../src/ck_ht.c
 	$(CC) $(CFLAGS) -o serial serial.c ../../../src/ck_ht.c
 
+serial.delete: serial.c ../../../include/ck_ht.h ../../../src/ck_ht.c
+	$(CC) $(CFLAGS) -DHT_DELETE -o serial.delete serial.c ../../../src/ck_ht.c
+
+parallel_bytestring.delete: parallel_bytestring.c ../../../include/ck_ht.h ../../../src/ck_ht.c ../../../src/ck_epoch.c
+	$(CC) $(PTHREAD_CFLAGS) $(CFLAGS) -DHT_DELETE -o parallel_bytestring.delete parallel_bytestring.c ../../../src/ck_ht.c ../../../src/ck_epoch.c
+
 parallel_bytestring: parallel_bytestring.c ../../../include/ck_ht.h ../../../src/ck_ht.c ../../../src/ck_epoch.c
 	$(CC) $(PTHREAD_CFLAGS) $(CFLAGS) -o parallel_bytestring parallel_bytestring.c ../../../src/ck_ht.c ../../../src/ck_epoch.c
 
diff --git a/regressions/ck_ht/benchmark/parallel_bytestring.c b/regressions/ck_ht/benchmark/parallel_bytestring.c
index f530788..8792bdc 100644
--- a/regressions/ck_ht/benchmark/parallel_bytestring.c
+++ b/regressions/ck_ht/benchmark/parallel_bytestring.c
@@ -124,11 +124,16 @@ static struct ck_malloc my_allocator = {
 static void
 table_init(void)
 {
+	unsigned int mode = CK_HT_MODE_BYTESTRING;
+
+#ifdef HT_DELETE
+	mode |= CK_HT_WORKLOAD_DELETE;
+#endif
 
 	ck_epoch_init(&epoch_ht);
 	ck_epoch_register(&epoch_ht, &epoch_wr);
 	common_srand48((long int)time(NULL));
-	if (ck_ht_init(&ht, CK_HT_MODE_BYTESTRING, NULL, &my_allocator, 8, common_lrand48()) == false) {
+	if (ck_ht_init(&ht, mode, NULL, &my_allocator, 8, common_lrand48()) == false) {
 		perror("ck_ht_init");
 		exit(EXIT_FAILURE);
 	}
diff --git a/regressions/ck_ht/benchmark/parallel_direct.c b/regressions/ck_ht/benchmark/parallel_direct.c
index 94e3e22..093c75b 100644
--- a/regressions/ck_ht/benchmark/parallel_direct.c
+++ b/regressions/ck_ht/benchmark/parallel_direct.c
@@ -280,6 +280,7 @@ main(int argc, char *argv[])
 	if (argc < 2) {
 		fprintf(stderr, "Usage: parallel <#entries> [<interval length> <initial size> <readers>\n"
 		    " <probability of replacement> <probability of deletion> <epoch threshold>]\n");
+		exit(EXIT_FAILURE);
 	}
 
 	if (argc >= 3)
diff --git a/regressions/ck_ht/benchmark/serial.c b/regressions/ck_ht/benchmark/serial.c
index 6189820..776f021 100644
--- a/regressions/ck_ht/benchmark/serial.c
+++ b/regressions/ck_ht/benchmark/serial.c
@@ -71,9 +71,14 @@ static struct ck_malloc my_allocator = {
 static void
 table_init(void)
 {
+	unsigned int mode = CK_HT_MODE_BYTESTRING;
+
+#ifdef HT_DELETE
+	mode |= CK_HT_WORKLOAD_DELETE;
+#endif
 
 	common_srand48((long int)time(NULL));
-	if (ck_ht_init(&ht, CK_HT_MODE_BYTESTRING, NULL, &my_allocator, 8, common_lrand48()) == false) {
+	if (ck_ht_init(&ht, mode, NULL, &my_allocator, 8, common_lrand48()) == false) {
 		perror("ck_ht_init");
 		exit(EXIT_FAILURE);
 	}
diff --git a/regressions/ck_ht/validate/Makefile b/regressions/ck_ht/validate/Makefile
index 5942975..cb5682c 100644
--- a/regressions/ck_ht/validate/Makefile
+++ b/regressions/ck_ht/validate/Makefile
@@ -1,14 +1,18 @@
 .PHONY: check clean distribution
 
-OBJECTS=serial
+OBJECTS=serial serial.delete
 
 all: $(OBJECTS)
 
 serial: serial.c ../../../include/ck_ht.h ../../../src/ck_ht.c
 	$(CC) $(CFLAGS) -o serial serial.c ../../../src/ck_ht.c
 
+serial.delete: serial.c ../../../include/ck_ht.h ../../../src/ck_ht.c
+	$(CC) $(CFLAGS) -DHT_DELETE -o serial.delete serial.c ../../../src/ck_ht.c
+
 check: all
 	./serial
+	./serial.delete
 
 clean:
 	rm -rf *~ *.o $(OBJECTS) *.dSYM *.exe
diff --git a/regressions/ck_ht/validate/serial.c b/regressions/ck_ht/validate/serial.c
index 446da5c..30e73a8 100644
--- a/regressions/ck_ht/validate/serial.c
+++ b/regressions/ck_ht/validate/serial.c
@@ -77,8 +77,13 @@ main(void)
 	ck_ht_hash_t h;
 	ck_ht_iterator_t iterator = CK_HT_ITERATOR_INITIALIZER;
 	ck_ht_entry_t *cursor;
+	unsigned int mode = CK_HT_MODE_BYTESTRING;
 
-	if (ck_ht_init(&ht, CK_HT_MODE_BYTESTRING, NULL, &my_allocator, 8, 6602834) == false) {
+#ifdef HT_DELETE
+	mode |= CK_HT_WORKLOAD_DELETE;
+#endif
+
+	if (ck_ht_init(&ht, mode, NULL, &my_allocator, 16, 6602834) == false) {
 		perror("ck_ht_init");
 		exit(EXIT_FAILURE);
 	}
@@ -187,7 +192,7 @@ main(void)
 		}
 	}
 
-	if (ck_ht_gc(&ht, 0, 0) == false) {
+	if (ck_ht_gc(&ht, 0, 27) == false) {
 		ck_error("ck_ht_gc\n");
 	}