diff --git a/lib/Makefile.Watcom b/lib/Makefile.Watcom
index 08507d0ec..0c20661b3 100644
--- a/lib/Makefile.Watcom
+++ b/lib/Makefile.Watcom
@@ -75,7 +75,7 @@ OBJS = $(OBJ_DIR)\base64.obj           $(OBJ_DIR)\connect.obj        &
        $(OBJ_DIR)\curl_rand.obj        $(OBJ_DIR)\curl_memrchr.obj   &
        $(OBJ_DIR)\imap.obj             $(OBJ_DIR)\pop3.obj           &
        $(OBJ_DIR)\smtp.obj             $(OBJ_DIR)\pingpong.obj       &
-       $(OBJ_DIR)\rtsp.obj
+       $(OBJ_DIR)\rtsp.obj             $(OBJ_DIR)\curl_threads.obj
 
 #
 # Use $(OBJS) as a template to generate $(OBJS_STAT) and $(OBJS_DYN).
diff --git a/lib/Makefile.riscos b/lib/Makefile.riscos
index e2b063a86..56472aeb1 100644
--- a/lib/Makefile.riscos
+++ b/lib/Makefile.riscos
@@ -14,7 +14,8 @@ objs =	o.base64 o.connect o.cookie o.dict \
 	o.strequal o.strtok o.telnet o.timeval \
 	o.transfer o.url o.version o.strtoofft o.sslgen o.gtls \
 	o.rawstr o.curl_addrinfo o.slist o.nonblock o.curl_rand \
-	o.curl_memrchr o.imap o.pop3 o.smtp o.pingpong o.rtsp
+	o.curl_memrchr o.imap o.pop3 o.smtp o.pingpong o.rtsp \
+	o.curl_threads
 
 
 # Compile options:
@@ -44,6 +45,9 @@ o.curl_memrchr:	c.curl_memrchr
 o.curl_rand:	c.curl_rand
 		gcc $(compileropts) -c -o curl_rand.o c.curl_rand
 
+o.curl_threads:	c.curl_threads
+		gcc $(compileropts) -c -o curl_threads.o c.curl_threads
+
 o.dict:	c.dict
 		gcc $(compileropts) -c -o dict.o c.dict
 
diff --git a/lib/Makefile.vc6 b/lib/Makefile.vc6
index fece41647..442595596 100644
--- a/lib/Makefile.vc6
+++ b/lib/Makefile.vc6
@@ -453,6 +453,7 @@ X_OBJS= \
 	$(DIROBJ)\curl_memrchr.obj \
 	$(DIROBJ)\curl_rand.obj \
 	$(DIROBJ)\curl_sspi.obj \
+	$(DIROBJ)\curl_threads.obj \
 	$(DIROBJ)\dict.obj \
 	$(DIROBJ)\easy.obj \
 	$(DIROBJ)\escape.obj \
diff --git a/lib/makefile.amiga b/lib/makefile.amiga
index 0863f2cf4..7d1b062c7 100644
--- a/lib/makefile.amiga
+++ b/lib/makefile.amiga
@@ -22,7 +22,7 @@ OBJS = amigaos.c \
   inet_ntop.c parsedate.c select.c gtls.c sslgen.c tftp.c splay.c	\
   strdup.c socks.c ssh.c nss.c qssl.c rawstr.c curl_addrinfo.c          \
   socks_gssapi.c socks_sspi.c curl_sspi.c slist.c nonblock.c		\
-  curl_memrchr.c imap.c pop3.c smtp.c pingpong.c rtsp.c
+  curl_memrchr.c imap.c pop3.c smtp.c pingpong.c rtsp.c curl_threads.c
 
 all:	$(OBJS:.c=.o)
 	ar cru libcurl.a $(OBJS:.c=.o)