diff --git dapl/udapl/linux/dapl_osd.h dapl/udapl/linux/dapl_osd.h
index 2b255d0..d9362f5 100644
--- dapl/udapl/linux/dapl_osd.h
+++ dapl/udapl/linux/dapl_osd.h
@@ -51,7 +51,7 @@
 
 #if !defined (__i386__) && !defined (__ia64__) && !defined(__x86_64__) && \
     !defined(__PPC__) && !defined(__PPC64__) && !defined(__s390x__) && \
-    !defined(__aarch64__)
+    !defined(__aarch64__) && !defined(__s390__)
 #error UNDEFINED ARCH
 #endif
 
@@ -160,7 +160,7 @@ int dapl_os_get_env_val (
 
 /* atomic functions */
 
-#ifdef __s390x__
+#if defined(__s390x__) || defined(__s390__)
 #define DAPL_CS_ADD(ptr, op_val) ({			\
 	int old_val, new_val;				\
 	__asm__ __volatile__(				\
@@ -199,7 +199,7 @@ dapl_os_atomic_inc (
 #else
 	IA64_FETCHADD(old_value,v,1,4);
 #endif
-#elif defined(__s390x__)
+#elif defined(__s390x__) || defined(__s390__)
 	DAT_COUNT	tmp;
 	DAT_COUNT	delta = 1;
 
@@ -245,7 +245,7 @@ dapl_os_atomic_dec (
 #else
 	IA64_FETCHADD(old_value,v,-1,4);
 #endif
-#elif defined(__s390x__)
+#elif defined(__s390x__) || defined(__s390__)
 	DAT_COUNT	tmp;
 	DAT_COUNT	delta = -1;
 
@@ -307,7 +307,7 @@ dapl_os_atomic_assign (
 #else
     current_value = ia64_cmpxchg(acq,v,match_value,new_value,4);
 #endif /* __ia64__ */
-#elif defined(__s390x__)
+#elif defined(__s390x__) || defined(__s390__)
 	__asm__ __volatile__(
 		"	cs	%0,%2,%1\n"
 		: "+d" (match_value), "=Q" (*v)