diff --git a/src/host/buildvm.c b/src/host/buildvm.c
index 57b4dc97..ad2a8171 100644
--- a/src/host/buildvm.c
+++ b/src/host/buildvm.c
@@ -65,6 +65,8 @@ static int collect_reloc(BuildCtx *ctx, uint8_t *addr, int idx, int type);
 #include "../dynasm/dasm_ppc.h"
 #elif LJ_TARGET_MIPS
 #include "../dynasm/dasm_mips.h"
+#elif LJ_TARGET_S390X
+#include "../dynasm/dasm_s390x.h"
 #else
 #error "No support for this architecture (yet)"
 #endif
diff --git a/src/lj_ccall.h b/src/lj_ccall.h
index d97227a6..2a10a5e8 100644
--- a/src/lj_ccall.h
+++ b/src/lj_ccall.h
@@ -126,6 +126,17 @@ typedef union FPRArg {
   struct { LJ_ENDIAN_LOHI(float f; , float g;) };
 } FPRArg;
 
+#elif LJ_TARGET_S390X
+
+#define CCALL_NARG_GPR		5	/* GPR 2,3,4,5,6 */
+#define CCALL_NARG_FPR		4	/* FPR 0,2,4,8 */
+#define CCALL_NRET_GPR		1	/* GPR 2 */
+#define CCALL_NRET_FPR		1	/* FPR 0 */
+#define CCALL_SPS_EXTRA		20	/* 160-byte callee save area (not sure if this is the right place) */
+#define CCALL_SPS_FREE		0
+
+typedef intptr_t GPRArg;
+typedef double FPRArg;
 #else
 #error "Missing calling convention definitions for this architecture"
 #endif