diff --git a/gcc-tools.jam b/gcc-tools.jam
index ee3bb1cd9..cfe9d0731 100644
--- a/gcc-tools.jam
+++ b/gcc-tools.jam
@@ -131,6 +131,10 @@ else if $(UNIX)
         {
         # gcc on IRIX does not support multi-threading, don't set anything here.
         }
+    case HP_UX :
+        {
+        # gcc on HP-UX does not support multi-threading, don't set anything here
+        }
     case * :
         {
         flags gcc CFLAGS <threading>multi : -pthread ;
diff --git a/v1/gcc-tools.jam b/v1/gcc-tools.jam
index ee3bb1cd9..cfe9d0731 100644
--- a/v1/gcc-tools.jam
+++ b/v1/gcc-tools.jam
@@ -131,6 +131,10 @@ else if $(UNIX)
         {
         # gcc on IRIX does not support multi-threading, don't set anything here.
         }
+    case HP_UX :
+        {
+        # gcc on HP-UX does not support multi-threading, don't set anything here
+        }
     case * :
         {
         flags gcc CFLAGS <threading>multi : -pthread ;