diff --git a/Makefile b/Makefile
index 551bde9ff..82f89b7b6 100644
--- a/Makefile
+++ b/Makefile
@@ -565,9 +565,11 @@ EXTLIBS =
 
 ifeq ($(uname_S),Linux)
 	NO_STRLCPY = YesPlease
+	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),GNU/kFreeBSD)
 	NO_STRLCPY = YesPlease
+	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),UnixWare)
 	CC = cc
@@ -665,6 +667,7 @@ ifeq ($(uname_S),FreeBSD)
 	BASIC_CFLAGS += -I/usr/local/include
 	BASIC_LDFLAGS += -L/usr/local/lib
 	DIR_HAS_BSD_GROUP_SEMANTICS = YesPlease
+	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),OpenBSD)
 	NO_STRCASESTR = YesPlease
@@ -672,6 +675,7 @@ ifeq ($(uname_S),OpenBSD)
 	NEEDS_LIBICONV = YesPlease
 	BASIC_CFLAGS += -I/usr/local/include
 	BASIC_LDFLAGS += -L/usr/local/lib
+	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),NetBSD)
 	ifeq ($(shell expr "$(uname_R)" : '[01]\.'),2)
@@ -680,6 +684,7 @@ ifeq ($(uname_S),NetBSD)
 	BASIC_CFLAGS += -I/usr/pkg/include
 	BASIC_LDFLAGS += -L/usr/pkg/lib
 	ALL_LDFLAGS += -Wl,-rpath,/usr/pkg/lib
+	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),AIX)
 	NO_STRCASESTR=YesPlease