diff --git a/py/asmarm.c b/py/asmarm.c
index 2f7556f16f..2c389ac8ce 100644
--- a/py/asmarm.c
+++ b/py/asmarm.c
@@ -179,6 +179,12 @@ STATIC uint asm_arm_op_sub_reg(uint rd, uint rn, uint rm) {
     return 0x0400000 | (rn << 16) | (rd << 12) | rm;
 }
 
+STATIC uint asm_arm_op_mul_reg(uint rd, uint rm, uint rs) {
+    // mul rd, rm, rs
+    assert(rd != rm);
+    return 0x0000090 | (rd << 16) | (rs << 8) | rm;
+}
+
 STATIC uint asm_arm_op_and_reg(uint rd, uint rn, uint rm) {
     // and rd, rn, rm
     return 0x0000000 | (rn << 16) | (rd << 12) | rm;
@@ -340,6 +346,12 @@ void asm_arm_sub_reg_reg_reg(asm_arm_t *as, uint rd, uint rn, uint rm) {
     emit_al(as, asm_arm_op_sub_reg(rd, rn, rm));
 }
 
+void asm_arm_mul_reg_reg_reg(asm_arm_t *as, uint rd, uint rs, uint rm) {
+    // rs and rm are swapped because of restriction rd!=rm
+    // mul rd, rm, rs
+    emit_al(as, asm_arm_op_mul_reg(rd, rm, rs));
+}
+
 void asm_arm_and_reg_reg_reg(asm_arm_t *as, uint rd, uint rn, uint rm) {
     // and rd, rn, rm
     emit_al(as, asm_arm_op_and_reg(rd, rn, rm));
diff --git a/py/asmarm.h b/py/asmarm.h
index 20be84b97e..15e7a047b5 100644
--- a/py/asmarm.h
+++ b/py/asmarm.h
@@ -101,6 +101,7 @@ void asm_arm_cmp_reg_reg(asm_arm_t *as, uint rd, uint rn);
 // arithmetic
 void asm_arm_add_reg_reg_reg(asm_arm_t *as, uint rd, uint rn, uint rm);
 void asm_arm_sub_reg_reg_reg(asm_arm_t *as, uint rd, uint rn, uint rm);
+void asm_arm_mul_reg_reg_reg(asm_arm_t *as, uint rd, uint rn, uint rm);
 void asm_arm_and_reg_reg_reg(asm_arm_t *as, uint rd, uint rn, uint rm);
 void asm_arm_eor_reg_reg_reg(asm_arm_t *as, uint rd, uint rn, uint rm);
 void asm_arm_orr_reg_reg_reg(asm_arm_t *as, uint rd, uint rn, uint rm);
diff --git a/py/asmx64.c b/py/asmx64.c
index c4eb275cbc..0b7c87415a 100644
--- a/py/asmx64.c
+++ b/py/asmx64.c
@@ -453,6 +453,12 @@ void asm_x64_sub_r64_r64(asm_x64_t *as, int dest_r64, int src_r64) {
     asm_x64_generic_r64_r64(as, dest_r64, src_r64, OPCODE_SUB_R64_FROM_RM64);
 }
 
+void asm_x64_mul_r64_r64(asm_x64_t *as, int dest_r64, int src_r64) {
+    // imul reg64, reg/mem64 -- 0x0f 0xaf /r
+    asm_x64_write_byte_1(as, REX_PREFIX | REX_W | (dest_r64 < 8 ? 0 : REX_R) | (src_r64 < 8 ? 0 : REX_B));
+    asm_x64_write_byte_3(as, 0x0f, 0xaf, MODRM_R64(dest_r64) | MODRM_RM_REG | MODRM_RM_R64(src_r64));
+}
+
 /*
 void asm_x64_sub_i32_from_r32(asm_x64_t *as, int src_i32, int dest_r32) {
     if (SIGNED_FIT8(src_i32)) {
diff --git a/py/asmx64.h b/py/asmx64.h
index 0d3af9aa18..67ff2b4575 100644
--- a/py/asmx64.h
+++ b/py/asmx64.h
@@ -105,6 +105,7 @@ void asm_x64_shl_r64_cl(asm_x64_t* as, int dest_r64);
 void asm_x64_sar_r64_cl(asm_x64_t* as, int dest_r64);
 void asm_x64_add_r64_r64(asm_x64_t* as, int dest_r64, int src_r64);
 void asm_x64_sub_r64_r64(asm_x64_t* as, int dest_r64, int src_r64);
+void asm_x64_mul_r64_r64(asm_x64_t* as, int dest_r64, int src_r64);
 void asm_x64_cmp_r64_with_r64(asm_x64_t* as, int src_r64_a, int src_r64_b);
 void asm_x64_test_r8_with_r8(asm_x64_t* as, int src_r64_a, int src_r64_b);
 void asm_x64_setcc_r8(asm_x64_t* as, int jcc_type, int dest_r8);
diff --git a/py/asmx86.c b/py/asmx86.c
index 8a4383c82d..25f0db8852 100644
--- a/py/asmx86.c
+++ b/py/asmx86.c
@@ -369,6 +369,11 @@ STATIC void asm_x86_sub_r32_i32(asm_x86_t *as, int dest_r32, int src_i32) {
     }
 }
 
+void asm_x86_mul_r32_r32(asm_x86_t *as, int dest_r32, int src_r32) {
+    // imul reg32, reg/mem32 -- 0x0f 0xaf /r
+    asm_x86_write_byte_3(as, 0x0f, 0xaf, MODRM_R32(dest_r32) | MODRM_RM_REG | MODRM_RM_R32(src_r32));
+}
+
 #if 0
 /* shifts not tested */
 void asm_x86_shl_r32_by_imm(asm_x86_t *as, int r32, int imm) {
diff --git a/py/asmx86.h b/py/asmx86.h
index cb245f37d9..e0c57722ad 100644
--- a/py/asmx86.h
+++ b/py/asmx86.h
@@ -104,6 +104,7 @@ void asm_x86_shl_r32_cl(asm_x86_t* as, int dest_r32);
 void asm_x86_sar_r32_cl(asm_x86_t* as, int dest_r32);
 void asm_x86_add_r32_r32(asm_x86_t* as, int dest_r32, int src_r32);
 void asm_x86_sub_r32_r32(asm_x86_t* as, int dest_r32, int src_r32);
+void asm_x86_mul_r32_r32(asm_x86_t* as, int dest_r32, int src_r32);
 void asm_x86_cmp_r32_with_r32(asm_x86_t* as, int src_r32_a, int src_r32_b);
 void asm_x86_test_r8_with_r8(asm_x86_t* as, int src_r32_a, int src_r32_b);
 void asm_x86_setcc_r8(asm_x86_t* as, mp_uint_t jcc_type, int dest_r8);
diff --git a/py/emitnative.c b/py/emitnative.c
index 4a382a2736..34df2e034c 100644
--- a/py/emitnative.c
+++ b/py/emitnative.c
@@ -146,6 +146,7 @@
 #define ASM_AND_REG_REG(as, reg_dest, reg_src) asm_x64_and_r64_r64((as), (reg_dest), (reg_src))
 #define ASM_ADD_REG_REG(as, reg_dest, reg_src) asm_x64_add_r64_r64((as), (reg_dest), (reg_src))
 #define ASM_SUB_REG_REG(as, reg_dest, reg_src) asm_x64_sub_r64_r64((as), (reg_dest), (reg_src))
+#define ASM_MUL_REG_REG(as, reg_dest, reg_src) asm_x64_mul_r64_r64((as), (reg_dest), (reg_src))
 
 #define ASM_LOAD_REG_REG(as, reg_dest, reg_base) asm_x64_mov_mem64_to_r64((as), (reg_base), 0, (reg_dest))
 #define ASM_LOAD_REG_REG_OFFSET(as, reg_dest, reg_base, word_offset) asm_x64_mov_mem64_to_r64((as), (reg_base), 8 * (word_offset), (reg_dest))
@@ -290,6 +291,7 @@ STATIC byte mp_f_n_args[MP_F_NUMBER_OF] = {
 #define ASM_AND_REG_REG(as, reg_dest, reg_src) asm_x86_and_r32_r32((as), (reg_dest), (reg_src))
 #define ASM_ADD_REG_REG(as, reg_dest, reg_src) asm_x86_add_r32_r32((as), (reg_dest), (reg_src))
 #define ASM_SUB_REG_REG(as, reg_dest, reg_src) asm_x86_sub_r32_r32((as), (reg_dest), (reg_src))
+#define ASM_MUL_REG_REG(as, reg_dest, reg_src) asm_x86_mul_r32_r32((as), (reg_dest), (reg_src))
 
 #define ASM_LOAD_REG_REG(as, reg_dest, reg_base) asm_x86_mov_mem32_to_r32((as), (reg_base), 0, (reg_dest))
 #define ASM_LOAD_REG_REG_OFFSET(as, reg_dest, reg_base, word_offset) asm_x86_mov_mem32_to_r32((as), (reg_base), 4 * (word_offset), (reg_dest))
@@ -382,6 +384,7 @@ STATIC byte mp_f_n_args[MP_F_NUMBER_OF] = {
 #define ASM_AND_REG_REG(as, reg_dest, reg_src) asm_thumb_format_4((as), ASM_THUMB_FORMAT_4_AND, (reg_dest), (reg_src))
 #define ASM_ADD_REG_REG(as, reg_dest, reg_src) asm_thumb_add_rlo_rlo_rlo((as), (reg_dest), (reg_dest), (reg_src))
 #define ASM_SUB_REG_REG(as, reg_dest, reg_src) asm_thumb_sub_rlo_rlo_rlo((as), (reg_dest), (reg_dest), (reg_src))
+#define ASM_MUL_REG_REG(as, reg_dest, reg_src) asm_thumb_format_4((as), ASM_THUMB_FORMAT_4_MUL, (reg_dest), (reg_src))
 
 #define ASM_LOAD_REG_REG(as, reg_dest, reg_base) asm_thumb_ldr_rlo_rlo_i5((as), (reg_dest), (reg_base), 0)
 #define ASM_LOAD_REG_REG_OFFSET(as, reg_dest, reg_base, word_offset) asm_thumb_ldr_rlo_rlo_i5((as), (reg_dest), (reg_base), (word_offset))
@@ -473,6 +476,7 @@ STATIC byte mp_f_n_args[MP_F_NUMBER_OF] = {
 #define ASM_AND_REG_REG(as, reg_dest, reg_src) asm_arm_and_reg_reg_reg((as), (reg_dest), (reg_dest), (reg_src))
 #define ASM_ADD_REG_REG(as, reg_dest, reg_src) asm_arm_add_reg_reg_reg((as), (reg_dest), (reg_dest), (reg_src))
 #define ASM_SUB_REG_REG(as, reg_dest, reg_src) asm_arm_sub_reg_reg_reg((as), (reg_dest), (reg_dest), (reg_src))
+#define ASM_MUL_REG_REG(as, reg_dest, reg_src) asm_arm_mul_reg_reg_reg((as), (reg_dest), (reg_dest), (reg_src))
 
 #define ASM_LOAD_REG_REG(as, reg_dest, reg_base) asm_arm_ldr_reg_reg((as), (reg_dest), (reg_base), 0)
 #define ASM_LOAD_REG_REG_OFFSET(as, reg_dest, reg_base, word_offset) asm_arm_ldr_reg_reg((as), (reg_dest), (reg_base), 4 * (word_offset))
@@ -2029,6 +2033,9 @@ STATIC void emit_native_binary_op(emit_t *emit, mp_binary_op_t op) {
         } else if (op == MP_BINARY_OP_SUBTRACT || op == MP_BINARY_OP_INPLACE_SUBTRACT) {
             ASM_SUB_REG_REG(emit->as, REG_ARG_2, reg_rhs);
             emit_post_push_reg(emit, VTYPE_INT, REG_ARG_2);
+        } else if (op == MP_BINARY_OP_MULTIPLY || op == MP_BINARY_OP_INPLACE_MULTIPLY) {
+            ASM_MUL_REG_REG(emit->as, REG_ARG_2, reg_rhs);
+            emit_post_push_reg(emit, VTYPE_INT, REG_ARG_2);
         } else if (MP_BINARY_OP_LESS <= op && op <= MP_BINARY_OP_NOT_EQUAL) {
             // comparison ops are (in enum order):
             //  MP_BINARY_OP_LESS
diff --git a/tests/micropython/viper_binop_arith.py b/tests/micropython/viper_binop_arith.py
index d37450315f..4d711f1a9f 100644
--- a/tests/micropython/viper_binop_arith.py
+++ b/tests/micropython/viper_binop_arith.py
@@ -18,6 +18,17 @@ sub(42, 3)
 sub(-1, 2)
 sub(-42, -3)
 
+@micropython.viper
+def mul(x:int, y:int):
+    print(x * y)
+    print(y * x)
+mul(0, 1)
+mul(1, -1)
+mul(1, 2)
+mul(8, 3)
+mul(-3, 4)
+mul(-9, -6)
+
 @micropython.viper
 def shl(x:int, y:int):
     print(x << y)
diff --git a/tests/micropython/viper_binop_arith.py.exp b/tests/micropython/viper_binop_arith.py.exp
index 15abcc2451..156e3aff5b 100644
--- a/tests/micropython/viper_binop_arith.py.exp
+++ b/tests/micropython/viper_binop_arith.py.exp
@@ -14,6 +14,18 @@
 3
 -39
 39
+0
+0
+-1
+-1
+2
+2
+24
+24
+-12
+-12
+54
+54
 1
 8
 1073741824