diff --git a/sys/amd64/amd64/fpu.c b/sys/amd64/amd64/fpu.c
index eeb71f9db6b..3de758116fe 100644
--- a/sys/amd64/amd64/fpu.c
+++ b/sys/amd64/amd64/fpu.c
@@ -1003,6 +1003,7 @@ npxsetregs(td, addr)
 		intr_restore(s);
 		bcopy(addr, &td->td_pcb->pcb_save, sizeof(*addr));
 	}
+	curthread->td_pcb->pcb_flags |= PCB_NPXINITDONE;
 }
 
 static void
diff --git a/sys/amd64/isa/npx.c b/sys/amd64/isa/npx.c
index eeb71f9db6b..3de758116fe 100644
--- a/sys/amd64/isa/npx.c
+++ b/sys/amd64/isa/npx.c
@@ -1003,6 +1003,7 @@ npxsetregs(td, addr)
 		intr_restore(s);
 		bcopy(addr, &td->td_pcb->pcb_save, sizeof(*addr));
 	}
+	curthread->td_pcb->pcb_flags |= PCB_NPXINITDONE;
 }
 
 static void
diff --git a/sys/i386/isa/npx.c b/sys/i386/isa/npx.c
index eeb71f9db6b..3de758116fe 100644
--- a/sys/i386/isa/npx.c
+++ b/sys/i386/isa/npx.c
@@ -1003,6 +1003,7 @@ npxsetregs(td, addr)
 		intr_restore(s);
 		bcopy(addr, &td->td_pcb->pcb_save, sizeof(*addr));
 	}
+	curthread->td_pcb->pcb_flags |= PCB_NPXINITDONE;
 }
 
 static void