diff --git a/configure.ac b/configure.ac
index 9aadd028..6d5fe447 100644
--- a/configure.ac
+++ b/configure.ac
@@ -416,7 +416,8 @@ AC_ARG_ENABLE(sna,
 	      [SNA="$enableval"],
 	      [SNA=auto])
 
-AC_CHECK_HEADERS([dev/wscons/wsconsio.h alloca.h])
+AC_CHECK_HEADERS([dev/wscons/wsconsio.h])
+AC_FUNC_ALLOCA
 AC_HEADER_MAJOR
 
 if test "x$SNA" != "xno"; then
diff --git a/libobj/alloca.c b/libobj/alloca.c
new file mode 100644
index 00000000..883e1e9f
--- /dev/null
+++ b/libobj/alloca.c
@@ -0,0 +1,4 @@
+void *alloca(size_t sz)
+{
+	return NULL;
+}
diff --git a/src/sna/sna_display.c b/src/sna/sna_display.c
index cee4a726..d9b9923a 100644
--- a/src/sna/sna_display.c
+++ b/src/sna/sna_display.c
@@ -42,6 +42,15 @@
 
 #if HAVE_ALLOCA_H
 #include <alloca.h>
+#elif defined __GNUC__
+#define alloca __builtin_alloca
+#elif defined _AIX
+#define alloca __alloca
+#elif defined _MSC_VER
+#include <malloc.h>
+#define alloca _alloca
+#else
+void *alloca(size_t);
 #endif
 
 #include "sna.h"