diff --git a/modules/pam_unix/pam_unix.c b/modules/pam_unix/pam_unix.c
index ddcd81b..e214d65 100644
--- a/modules/pam_unix/pam_unix.c
+++ b/modules/pam_unix/pam_unix.c
@@ -31,7 +31,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $P4: //depot/projects/openpam/modules/pam_unix/pam_unix.c#3 $
+ * $P4: //depot/projects/openpam/modules/pam_unix/pam_unix.c#4 $
  */
 
 #include <sys/param.h>
@@ -42,6 +42,10 @@
 #include <string.h>
 #include <unistd.h>
 
+#ifdef __GLIBC__
+#include <crypt.h>
+#endif
+
 #include <security/pam_modules.h>
 #include <security/pam_appl.h>