Fix proprocessor directives for MBEDTLS_RIPEMD160_ALT
diff --git a/include/mbedtls/ripemd160.h b/include/mbedtls/ripemd160.h
index 93a16bc..3921e66 100644
--- a/include/mbedtls/ripemd160.h
+++ b/include/mbedtls/ripemd160.h
@@ -199,7 +199,7 @@
 #endif
 
 #else  /* MBEDTLS_RIPEMD160_ALT */
-#include "ripemd160.h"
+#include "ripemd160_alt.h"
 #endif /* MBEDTLS_RIPEMD160_ALT */
 
 #ifdef __cplusplus
diff --git a/library/ripemd160.c b/library/ripemd160.c
index 260fee6..b85b117 100644
--- a/library/ripemd160.c
+++ b/library/ripemd160.c
@@ -46,6 +46,8 @@
 #endif /* MBEDTLS_PLATFORM_C */
 #endif /* MBEDTLS_SELF_TEST */
 
+#if !defined(MBEDTLS_RIPEMD160_ALT)
+
 /*
  * 32-bit integer manipulation macros (little endian)
  */
@@ -393,6 +395,8 @@
     return( 0 );
 }
 
+#endif /* ! MBEDTLS_RIPEMD160_ALT */
+
 /*
  * output = RIPEMD-160( input buffer )
  */