diff --git a/bindings/java/hyperic_jni/jni-build.xml b/bindings/java/hyperic_jni/jni-build.xml
index b61af65a..034ec21f 100644
--- a/bindings/java/hyperic_jni/jni-build.xml
+++ b/bindings/java/hyperic_jni/jni-build.xml
@@ -328,7 +328,7 @@ USA.
         <compilerarg value="-g" if="jni.debug"/>
         <compilerarg value="-Wall"/>
         <compilerarg value="-Werror" if="jni.werror"/>
-        <compilerarg value="-m64" if="jni.usem64"/>
+        <compilerarg value="${jni.gccm}" if="jni.gccm"/>
         <defineset>
           <define name="${jni.define.name}_LINUX"/>
           <define name="_REENTRANT"/>
@@ -343,7 +343,7 @@ USA.
         <libset if="jni.dmalloc"
                 dir="${jni.dmalloc}/lib"
                 libs="dmallocth"/>
-        <linkerarg value="-m64" if="jni.usem64"/>
+        <linkerarg value="${jni.gccm}" if="jni.gccm"/>
       </linker>
 
       <!-- Darwin -->
diff --git a/bindings/java/hyperic_jni/src/org/hyperic/jni/ArchNameTask.java b/bindings/java/hyperic_jni/src/org/hyperic/jni/ArchNameTask.java
index 443dba89..e1c275d3 100644
--- a/bindings/java/hyperic_jni/src/org/hyperic/jni/ArchNameTask.java
+++ b/bindings/java/hyperic_jni/src/org/hyperic/jni/ArchNameTask.java
@@ -73,10 +73,16 @@ public class ArchNameTask extends Task {
             getProject().setProperty("jni.arch64", "true");
             if (ArchLoader.IS_LINUX) {
                 if (!osArch.equals("ia64")) {
-                    getProject().setProperty("jni.usem64", "true");        
+                    getProject().setProperty("jni.gccm", "-m64");
                 }
             }
         }
+        else {
+            if (ArchLoader.IS_LINUX && osArch.equals("s390")) {
+                //gcc defaults to m64 on s390x platforms
+                getProject().setProperty("jni.gccm", "-m31");
+            }
+        }
 
         if (ArchLoader.IS_DARWIN) {
             //default to most recent SDK