diff --git a/src/lang/Prolog.java b/src/lang/Prolog.java
index 8d4e4b6..20633f5 100644
--- a/src/lang/Prolog.java
+++ b/src/lang/Prolog.java
@@ -117,7 +117,7 @@
   private void initOnce() {
     if (pcl == null) pcl = new PrologClassLoader();
     if (internalDB == null) internalDB = new InternalDatabase();
-    if (streamManager == null) streamManager = new HashtableOfTerm();
+    if (streamManager == null) streamManager = new HashtableOfTerm(7);
   }
 
     /** Initializes this Prolog engine. */
diff --git a/src/lang/PrologControl.java b/src/lang/PrologControl.java
index 02bd6ae..00ffb2a 100644
--- a/src/lang/PrologControl.java
+++ b/src/lang/PrologControl.java
@@ -92,6 +92,9 @@
      */
     public void configureUserIO(InputStream in, OutputStream out,
         OutputStream err) {
+      if (engine.streamManager == null) {
+        engine.streamManager = new HashtableOfTerm(7);
+      }
       if (in != null) {
         engine.streamManager.put(
             SymbolTerm.intern("user_input"),