diff --git a/config.mak.in b/config.mak.in
index 717072943f..ea7705c1ed 100644
--- a/config.mak.in
+++ b/config.mak.in
@@ -51,3 +51,4 @@ OLD_ICONV=@OLD_ICONV@
 NO_DEFLATE_BOUND=@NO_DEFLATE_BOUND@
 FREAD_READS_DIRECTORIES=@FREAD_READS_DIRECTORIES@
 SNPRINTF_RETURNS_BOGUS=@SNPRINTF_RETURNS_BOGUS@
+PTHREAD_LIBS=@PTHREAD_LIBS@
diff --git a/configure.ac b/configure.ac
index a0d53f3124..3f058a087b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -479,6 +479,22 @@ AC_SUBST(NO_MKDTEMP)
 #
 # Define NO_SYMLINK_HEAD if you never want .git/HEAD to be a symbolic link.
 # Enable it on Windows.  By default, symrefs are still used.
+#
+# Define PTHREAD_LIBS to the linker flag used for Pthread support.
+AC_LANG_CONFTEST([AC_LANG_PROGRAM(
+  [[#include <pthread.h>]],
+  [[pthread_mutex_t test_mutex;]]
+)])
+${CC} -pthread conftest.c -o conftest.o > /dev/null 2>&1
+if test $? -eq 0;then
+ PTHREAD_LIBS="-pthread"
+else
+ ${CC} -lpthread conftest.c -o conftest.o > /dev/null 2>&1
+ if test $? -eq 0;then
+  PTHREAD_LIBS="-lpthread"
+ fi
+fi
+AC_SUBST(PTHREAD_LIBS)
 
 ## Site configuration (override autodetection)
 ## --with-PACKAGE[=ARG] and --without-PACKAGE