--- src/org/armedbear/lisp/Bignum.java.orig	2015-04-08 19:58:28.733403019 +0200
+++ src/org/armedbear/lisp/Bignum.java	2015-04-08 20:00:16.000073126 +0200
@@ -213,7 +213,7 @@
   @Override
   public boolean equalp(LispObject obj)
   {
-    if (obj.numberp())
+    if (obj != null && obj.numberp())
       return isEqualTo(obj);
     return false;
   }
--- src/org/armedbear/lisp/Complex.java.orig	2015-04-08 19:58:28.733403019 +0200
+++ src/org/armedbear/lisp/Complex.java	2015-04-08 20:00:02.993406043 +0200
@@ -143,7 +143,7 @@
   @Override
   public boolean equalp(LispObject obj)
   {
-    if (obj.numberp())
+    if (obj != null && obj.numberp())
       return isEqualTo(obj);
     return false;
   }
--- src/org/armedbear/lisp/DoubleFloat.java.orig	2015-04-08 19:58:28.736736351 +0200
+++ src/org/armedbear/lisp/DoubleFloat.java	2015-04-08 19:59:57.530072534 +0200
@@ -169,7 +169,7 @@
     @Override
     public boolean equalp(LispObject obj)
     {
-        if (obj.numberp())
+        if (obj != null && obj.numberp())
             return isEqualTo(obj);
         return false;
     }
--- src/org/armedbear/lisp/Fixnum.java.orig	2015-04-08 19:58:28.736736351 +0200
+++ src/org/armedbear/lisp/Fixnum.java	2015-04-08 19:59:46.683405519 +0200
@@ -228,7 +228,7 @@
   @Override
   public boolean equalp(LispObject obj)
   {
-    if (obj.numberp())
+    if (obj != null && obj.numberp())
       return isEqualTo(obj);
     return false;
   }
--- src/org/armedbear/lisp/Ratio.java.orig	2015-04-08 19:58:28.736736351 +0200
+++ src/org/armedbear/lisp/Ratio.java	2015-04-08 19:59:24.800071484 +0200
@@ -137,7 +137,7 @@
     @Override
     public boolean equalp(LispObject obj)
     {
-        if (obj.numberp())
+        if (obj != null && obj.numberp())
             return isEqualTo(obj);
         return false;
     }
--- src/org/armedbear/lisp/SingleFloat.java.orig	2015-04-08 19:58:28.736736351 +0200
+++ src/org/armedbear/lisp/SingleFloat.java	2015-04-08 19:59:09.080070979 +0200
@@ -169,7 +169,7 @@
     @Override
     public boolean equalp(LispObject obj)
     {
-        if (obj.numberp())
+        if (obj != null && obj.numberp())
             return isEqualTo(obj);
         return false;
     }