diff --git a/terminal/src/main/java/org/jline/terminal/impl/exec/ExecTerminalProvider.java b/terminal/src/main/java/org/jline/terminal/impl/exec/ExecTerminalProvider.java
index 6ab20ec66..a3ef547a7 100644
--- a/terminal/src/main/java/org/jline/terminal/impl/exec/ExecTerminalProvider.java
+++ b/terminal/src/main/java/org/jline/terminal/impl/exec/ExecTerminalProvider.java
@@ -45,6 +45,9 @@ public String name() {
     }
 
     public Pty current(SystemStream systemStream) throws IOException {
+        if (!isSystemStream(systemStream)) {
+            throw new IOException("Not a system stream: " + systemStream);
+        }
         return ExecPty.current(this, systemStream);
     }