diff --git a/extra/io/unix/launcher/launcher.factor b/extra/io/unix/launcher/launcher.factor
index 3cd21e6c51..769e905b6e 100755
--- a/extra/io/unix/launcher/launcher.factor
+++ b/extra/io/unix/launcher/launcher.factor
@@ -84,7 +84,7 @@ M: unix-io process-stream*
 ! On BSD and Mac OS X, we use kqueue() which scales better.
 : wait-for-processes ( -- ? )
     -1 0 <int> tuck WNOHANG waitpid
-    dup zero? [
+    dup 0 <= [
         2drop t
     ] [
         find-process dup [
diff --git a/extra/unix/unix.factor b/extra/unix/unix.factor
index 16b279765f..f5c484568e 100755
--- a/extra/unix/unix.factor
+++ b/extra/unix/unix.factor
@@ -13,7 +13,7 @@ TYPEDEF: longlong quad_t
 TYPEDEF: uint gid_t
 TYPEDEF: uint in_addr_t
 TYPEDEF: uint ino_t
-TYPEDEF: uint pid_t
+TYPEDEF: int pid_t
 TYPEDEF: uint socklen_t
 TYPEDEF: uint time_t
 TYPEDEF: uint uid_t