diff --git a/src/libpcp/src/util.c b/src/libpcp/src/util.c
index a09aa97..052c900 100644
--- a/src/libpcp/src/util.c
+++ b/src/libpcp/src/util.c
@@ -1157,7 +1157,16 @@ __pmProcessExists(pid_t pid)
 int
 __pmProcessTerminate(pid_t pid, int force)
 {
-    return kill(pid, force ? SIGKILL : SIGTERM);
+    if (pid != 0 && pid != -1)
+	return kill(pid, force ? SIGKILL : SIGTERM);
+    else {
+	/*
+	 * sending KILL or TERM to all processes in a process group
+	 * is just too dangerous ...
+	 */
+	return -EINVAL;
+    }
+
 }
 #elif !defined(IS_MINGW)
 !bozo!