diff --git a/build.xml b/build.xml
index 7007f750f..e4e313b36 100644
--- a/build.xml
+++ b/build.xml
@@ -505,8 +505,11 @@
         <copy todir="pkg-temp/lib/wrapper/solaris/">
             <fileset dir="installer/lib/wrapper/solaris/" />
         </copy>
-        <copy todir="pkg-temp/lib/wrapper/linux-arm/">
-            <fileset dir="installer/lib/wrapper/linux-arm/" />
+        <copy todir="pkg-temp/lib/wrapper/linux-armv7/">
+            <fileset dir="installer/lib/wrapper/linux-armv7/" />
+        </copy>
+        <copy todir="pkg-temp/lib/wrapper/linux-armv5/">
+            <fileset dir="installer/lib/wrapper/linux-armv5/" />
         </copy>
     </target>
 
diff --git a/core/java/src/net/i2p/util/NativeBigInteger.java b/core/java/src/net/i2p/util/NativeBigInteger.java
index 312babe83..d90ca32c2 100644
--- a/core/java/src/net/i2p/util/NativeBigInteger.java
+++ b/core/java/src/net/i2p/util/NativeBigInteger.java
@@ -9,6 +9,7 @@ package net.i2p.util;
  */
 
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
@@ -28,6 +29,7 @@ import freenet.support.CPUInformation.VIACPUInfo;
 import freenet.support.CPUInformation.UnknownCPUException;
 
 import net.i2p.I2PAppContext;
+import net.i2p.data.DataHelper;
 
 /**
  * <p>BigInteger that takes advantage of the jbigi library for the modPow operation,
@@ -629,6 +631,35 @@ public class NativeBigInteger extends BigInteger {
                 // athlon64_64 is always a fallback for 64 bit
                 rv.add(_libPrefix + getMiddleName1() + JBIGI_OPTIMIZATION_ATHLON64 + "_64" + _libSuffix);
             }
+
+            if (_isArm) {
+                InputStream in = null;
+                try {
+                    in = new FileInputStream("/proc/cpuinfo");
+                    while (true) {
+                        String line = DataHelper.readLine(in);
+                        if (line == null)
+                            break;
+                        if (!line.startsWith("CPU architecture"))
+                            continue;
+                        //CPU architecture: 5TEJ
+                        //CPU architecture: 7
+                        int colon = line.indexOf(": ");
+                        String sver = line.substring(colon + 2, colon + 3);
+                        int ver = Integer.parseInt(sver);
+                        // add libjbigi-linux-armv7.so, libjbigi-linux-armv6.so, ...
+                        for (int i = ver; i >= 3; i--) {
+                            rv.add(_libPrefix + getMiddleName1() + primary + 'v' + i + _libSuffix);
+                        }
+                        break;
+                    }
+                } catch (NumberFormatException nfe) {
+                } catch (IOException ioe) {
+                } finally {
+                    if (in != null) try { in.close(); } catch (IOException ioe) {}
+                }
+            }
+
             // the preferred selection
             rv.add(_libPrefix + getMiddleName1() + primary + _libSuffix);
 
diff --git a/history.txt b/history.txt
index d207ca1e9..9c5f2ecf0 100644
--- a/history.txt
+++ b/history.txt
@@ -1,5 +1,7 @@
 2011-07-26 zzz
   * Installer: The previous wrapper files only work on armv7
+  * NativeBigInteger: Move libjbigi-linux-arm.so to libjbigi-linux-armv7.so,
+                      do ARM version detection in NBI.
   * NetDB:
     - Explore even more aggressively at startup
     - Increase SingleSearchJob timeout
diff --git a/installer/lib/jbigi/libjbigi-linux-arm.so b/installer/lib/jbigi/libjbigi-linux-armv7.so
similarity index 100%
rename from installer/lib/jbigi/libjbigi-linux-arm.so
rename to installer/lib/jbigi/libjbigi-linux-armv7.so