diff --git a/INSTALL b/INSTALL
index c850a12e..80c7bb2b 100755
--- a/INSTALL
+++ b/INSTALL
@@ -12,7 +12,7 @@ if [ `uname` = Linux ]; then
 	# to use pthreads or not.  On 2.6 versions that aren't
 	# linking with NPTL by default, pretend to be an older kernel.
 	echo "Running on Linux: checking for NPTL..."
-	gcc lib/linux-isnptl.c
+	gcc lib/linux-isnptl.c -lpthread
 	if ./a.out
 	then	
 		echo "	NPTL found."