diff --git a/library/alignment.h b/library/alignment.h
index 60e5dba138..6394be2f36 100644
--- a/library/alignment.h
+++ b/library/alignment.h
@@ -24,38 +24,32 @@
 #define MBEDTLS_LIBRARY_ALIGNMENT_H
 
 #include <stdint.h>
+#include <string.h>
 
-/** MBEDTLS_ALLOW_UNALIGNED_ACCESS is defined for architectures where unaligned
- * memory accesses are safe and performant.
+/**
+ * Read the unsigned 32 bits integer from the given address, which need not
+ * be aligned.
  *
- * Unaligned accesses must be made via the UNALIGNED_UINT32_T type
- * defined here.
- *
- * This list is incomplete.
+ * \param   p pointer to 4 bytes of data
  */
-#if defined(__i386__) || defined(__amd64__) || defined( __x86_64__) \
-    || defined(__ARM_FEATURE_UNALIGNED) \
-    || defined(__aarch64__) \
-    || defined(__ARM_ARCH_8__) || defined(__ARM_ARCH_8A__) || defined(__ARM_ARCH_8M__) \
-    || defined(__ARM_ARCH_7A__)
-#if (defined(__GNUC__) && __GNUC__ >= 4) \
-    || (defined(__clang__) && __has_attribute(aligned)) \
-    || (defined(__ARMCC_VERSION) && __ARMCC_VERSION >= 5000000 )
-    /* GCC, Clang and armcc */
-#define MBEDTLS_ALLOW_UNALIGNED_ACCESS
-__attribute__((aligned(1))) typedef uint32_t mbedtls_unaligned_uint32_t;
-#define UNALIGNED_UINT32_T mbedtls_unaligned_uint32_t
-#elif defined(_MSC_VER)
-    /* MSVC */
-#define MBEDTLS_ALLOW_UNALIGNED_ACCESS
-#define UNALIGNED_UINT32_T __declspec(align(1)) uint32_t
-#elif (defined __ICCARM__)
-    /* IAR - this is disabled until we have the opportunity to test it */
-#undef MBEDTLS_ALLOW_UNALIGNED_ACCESS
-#define UNALIGNED_UINT32_T _Pragma("data_alignment = 1") uint32_t
-#endif
-#endif
+static inline uint32_t mbedtls_get_unaligned_uint32( void const *p )
+{
+    uint32_t r;
+    memcpy( &r, p, 4 );
+    return r;
+}
 
+/**
+ * Write the unsigned 32 bits integer to the given address, which need not
+ * be aligned.
+ *
+ * \param   p pointer to 4 bytes of data
+ * \param   x data to write
+ */
+static inline void mbedtls_put_unaligned_uint32( void *p, uint32_t x )
+{
+    memcpy(p, &x, 4);
+}
 
 /** Byte Reading Macros
  *
diff --git a/library/common.h b/library/common.h
index 63c936fe5d..9dbe21b880 100644
--- a/library/common.h
+++ b/library/common.h
@@ -88,24 +88,16 @@ extern void (*mbedtls_test_hook_test_fail)( const char * test, int line, const c
  */
 inline void mbedtls_xor( unsigned char *r, unsigned char const *a, unsigned char const *b, size_t n )
 {
-#if defined(MBEDTLS_ALLOW_UNALIGNED_ACCESS)
-     UNALIGNED_UINT32_T *a32 = (uint32_t *)a;
-     UNALIGNED_UINT32_T *b32 = (uint32_t *)b;
-     UNALIGNED_UINT32_T *r32 = (uint32_t *)r;
-    for ( size_t i = 0; i < ( n >> 2 ); i++ )
+    size_t i;
+    for ( i = 0; (i + 4) < n; i+= 4 )
     {
-        r32[i] = a32[i] ^ b32[i];
+        uint32_t x = mbedtls_get_unaligned_uint32(a + i) ^ mbedtls_get_unaligned_uint32(b + i);
+        mbedtls_put_unaligned_uint32(r + i, x);
     }
-    for ( size_t i = n - ( n % 4 ) ; i < n; i++ )
+    for ( ; i < n; i++ )
     {
         r[i] = a[i] ^ b[i];
     }
-#else
-    for ( size_t i = 0; i < n; i++ )
-    {
-        r[i] = a[i] ^ b[i];
-    }
-#endif
 }
 
 /* Fix MSVC C99 compatible issue