diff --git a/xs/src/avrdude/CMakeLists.txt b/xs/src/avrdude/CMakeLists.txt
index d7a0f2021..043f8fb7b 100644
--- a/xs/src/avrdude/CMakeLists.txt
+++ b/xs/src/avrdude/CMakeLists.txt
@@ -1,5 +1,6 @@
 
 
+add_definitions(-D_BSD_SOURCE -D_DEFAULT_SOURCE)   # To enable various useful macros and functions on Unices
 remove_definitions(-D_UNICODE -DUNICODE)
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 set(CMAKE_C_STANDARD 99)
diff --git a/xs/src/avrdude/buspirate.c b/xs/src/avrdude/buspirate.c
index a06019b9c..435c4ce53 100644
--- a/xs/src/avrdude/buspirate.c
+++ b/xs/src/avrdude/buspirate.c
@@ -41,9 +41,6 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-#if defined(WIN32NATIVE)
-#  include <malloc.h>  /* for alloca() */
-#endif
 
 #include "avrdude.h"
 #include "libavrdude.h"
diff --git a/xs/src/avrdude/libavrdude.h b/xs/src/avrdude/libavrdude.h
index 786b4d961..42c413ed7 100644
--- a/xs/src/avrdude/libavrdude.h
+++ b/xs/src/avrdude/libavrdude.h
@@ -933,6 +933,13 @@ int read_config(const char * file);
 }
 #endif
 
+// Header file for alloca()
+#if defined(WIN32NATIVE)
+#  include <malloc.h>
+#else
+#  include <alloca.h>
+#endif
+
 
 /* formerly confwin.h */
 
diff --git a/xs/src/avrdude/ser_posix.c b/xs/src/avrdude/ser_posix.c
index e71c40179..81e05da2e 100644
--- a/xs/src/avrdude/ser_posix.c
+++ b/xs/src/avrdude/ser_posix.c
@@ -25,8 +25,6 @@
 
 #if !defined(WIN32NATIVE)
 
-#define _BSD_SOURCE    // Needed to enable various macros (such as h_addr)
-
 #include <ctype.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/xs/src/avrdude/stk500.c b/xs/src/avrdude/stk500.c
index 987589305..5d2d3c1df 100644
--- a/xs/src/avrdude/stk500.c
+++ b/xs/src/avrdude/stk500.c
@@ -35,9 +35,6 @@
 #include <string.h>
 #include <errno.h>
 #include <unistd.h>
-#if defined(WIN32NATIVE)
-#  include <malloc.h>  /* for alloca() */
-#endif
 
 #include "avrdude.h"
 #include "libavrdude.h"