diff --git a/hio/lib/hio-pac1.h b/hio/lib/hio-pac1.h
index d6e37c7..ecb5504 100644
--- a/hio/lib/hio-pac1.h
+++ b/hio/lib/hio-pac1.h
@@ -22,7 +22,10 @@
     THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#if defined(__GNUC__)
+
+#if defined(__GNUC__) && (__GNUC__ >= 4)
+#	pragma pack(push,1)
+#elif defined(__GNUC__)
 #	pragma pack(1)
 #elif defined(__HP_aCC) || defined(__HP_cc)
 #	pragma PACK 1
diff --git a/hio/lib/hio-upac.h b/hio/lib/hio-upac.h
index 8f4c3aa..82bb429 100644
--- a/hio/lib/hio-upac.h
+++ b/hio/lib/hio-upac.h
@@ -22,7 +22,10 @@
     THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#if defined(__GNUC__)
+
+#if defined(__GNUC__) && (__GNUC__ >= 4)
+#	pragma pack(pop)
+#elif defined(__GNUC__)
 #	pragma pack()
 #elif defined(__HP_aCC) || defined(__HP_cc)
 #	pragma PACK