diff --git a/src/syncdraw/crt.c b/src/syncdraw/crt.c
index 66f9cff802fb8b8245b6701146c47b58e0ae26f4..97f0a4ab73e8714b2aaa012c9fdf42b42d1fe55f 100644
--- a/src/syncdraw/crt.c
+++ b/src/syncdraw/crt.c
@@ -1,6 +1,9 @@
 #include <stdlib.h>
 
 #include <ciolib.h>
+#if defined(_WIN32)
+ #include <malloc.h>	/* alloca() on Win32 */
+#endif
 
 #include "attrs.h"
 
diff --git a/src/syncdraw/effekt.c b/src/syncdraw/effekt.c
index 502061702adcc3da3a1d7b55a3ffc16443850764..d2ff469399a7923c3659ad7ec729514fa5c0baa6 100644
--- a/src/syncdraw/effekt.c
+++ b/src/syncdraw/effekt.c
@@ -3,6 +3,9 @@
 #include <stdlib.h>
 
 #include <ciolib.h>
+#if defined(_WIN32)
+ #include <malloc.h>	/* alloca() on Win32 */
+#endif
 
 #include "crt.h"
 #include "key.h"
diff --git a/src/syncdraw/miscfunctions.c b/src/syncdraw/miscfunctions.c
index e789131daf3c171e4da85bd253eddc3d8e0d9b45..342dd89b2f4406cc0269ac2f075831e08a2ec319 100644
--- a/src/syncdraw/miscfunctions.c
+++ b/src/syncdraw/miscfunctions.c
@@ -5,6 +5,9 @@
 
 #include <ciolib.h>
 #include <gen_defs.h>
+#if defined(_WIN32)
+ #include <malloc.h>	/* alloca() on Win32 */
+#endif
 
 #include "crt.h"
 #include "syncdraw.h"