diff --git a/decode-test.c b/decode-test.c
index df576bf..591db7e 100644
--- a/decode-test.c
+++ b/decode-test.c
@@ -498,6 +498,19 @@ main(int argc, char** argv)
     TEST32("\xc4\xe3\x75\x4b\xc2\x80", "vblendvpd ymm0, ymm1, ymm2, ymm0"); // Bit 7 is ignored
     TEST64("\xc4\xe3\x75\x4b\xc2\x80", "vblendvpd ymm0, ymm1, ymm2, ymm8");
 
+    TEST("\xc4\xe2\x79\xdb\xc1", "vaesimc xmm0, xmm1");
+    TEST("\xc4\xe2\x7d\xdb\xc1", "UD"); // VEX.L != 0
+    TEST("\xc4\xe3\x79\xdf\xc1\xae", "vaeskeygenassist xmm0, xmm1, 0xae");
+    TEST("\xc4\xe3\x7d\xdf\xc1\xae", "UD"); // VEX.L != 0
+    TEST("\xc4\xe2\x71\xdc\xc2", "vaesenc xmm0, xmm1, xmm2");
+    TEST("\xc4\xe2\x75\xdc\xc2", "vaesenc ymm0, ymm1, ymm2");
+    TEST("\xc4\xe2\x71\xdd\xc2", "vaesenclast xmm0, xmm1, xmm2");
+    TEST("\xc4\xe2\x75\xdd\xc2", "vaesenclast ymm0, ymm1, ymm2");
+    TEST("\xc4\xe2\x71\xde\xc2", "vaesdec xmm0, xmm1, xmm2");
+    TEST("\xc4\xe2\x75\xde\xc2", "vaesdec ymm0, ymm1, ymm2");
+    TEST("\xc4\xe2\x71\xdf\xc2", "vaesdeclast xmm0, xmm1, xmm2");
+    TEST("\xc4\xe2\x75\xdf\xc2", "vaesdeclast ymm0, ymm1, ymm2");
+
     TEST("\xc4\xe2\x71\x92\xc0", "UD"); // Must have memory operand
     TEST("\xc4\xe2\x71\x92\x00", "UD"); // Must have SIB byte
     TEST("\xc4\xe2\x71\x92\x05\x00\x00\x00\x00", "UD"); // Must have SIB byte
diff --git a/encode-test.inc b/encode-test.inc
index 0485fc4..575f6d8 100644
--- a/encode-test.inc
+++ b/encode-test.inc
@@ -255,6 +255,17 @@ TEST("\xc4\xe2\xf1\x91\x04\xe7", VPGATHERQQ128rmr, 0, FE_XMM0, FE_MEMV(FE_DI, 8,
 TEST("\xc4\xe2\xf5\x91\x04\xff", VPGATHERQQ256rmr, 0, FE_XMM0, FE_MEMV(FE_DI, 8, FE_XMM7, 0), FE_XMM1);
 TEST("\xc4\xe2\xf5\x91\x04\xe7", VPGATHERQQ256rmr, 0, FE_XMM0, FE_MEMV(FE_DI, 8, FE_XMM4, 0), FE_XMM1);
 
+TEST("\xc4\xe2\x79\xdb\xc1", VAESIMCrr, 0, FE_XMM0, FE_XMM1);
+TEST("\xc4\xe3\x79\xdf\xc1\xae", VAESKEYGENASSISTrri, 0, FE_XMM0, FE_XMM1, (int8_t) 0xae);
+TEST("\xc4\xe2\x71\xdc\xc2", VAESENC128rrr, 0, FE_XMM0, FE_XMM1, FE_XMM2);
+TEST("\xc4\xe2\x75\xdc\xc2", VAESENC256rrr, 0, FE_XMM0, FE_XMM1, FE_XMM2);
+TEST("\xc4\xe2\x71\xdd\xc2", VAESENCLAST128rrr, 0, FE_XMM0, FE_XMM1, FE_XMM2);
+TEST("\xc4\xe2\x75\xdd\xc2", VAESENCLAST256rrr, 0, FE_XMM0, FE_XMM1, FE_XMM2);
+TEST("\xc4\xe2\x71\xde\xc2", VAESDEC128rrr, 0, FE_XMM0, FE_XMM1, FE_XMM2);
+TEST("\xc4\xe2\x75\xde\xc2", VAESDEC256rrr, 0, FE_XMM0, FE_XMM1, FE_XMM2);
+TEST("\xc4\xe2\x71\xdf\xc2", VAESDECLAST128rrr, 0, FE_XMM0, FE_XMM1, FE_XMM2);
+TEST("\xc4\xe2\x75\xdf\xc2", VAESDECLAST256rrr, 0, FE_XMM0, FE_XMM1, FE_XMM2);
+
 // Test ModRM encoding
 TEST("\x01\x00", ADD32mr, 0, FE_MEM(FE_AX, 0, FE_NOREG, 0), FE_AX);
 TEST("\x01\x04\x24", ADD32mr, 0, FE_MEM(FE_SP, 0, FE_NOREG, 0), FE_AX);
diff --git a/instrs.txt b/instrs.txt
index 0cb8ad7..8cb6141 100644
--- a/instrs.txt
+++ b/instrs.txt
@@ -880,10 +880,15 @@ NP.0f38f9/m            MR   My  Gy  -   -   MOVDIRI             F=MOVDIRI
 66.0f38df              RM   Vdq Wdq -   -   AESDECLAST          F=AESNI
 66.0f3adf              RMI  Vdq Wdq Ib  -   AESKEYGENASSIST     F=AESNI
 VEX.66.L0.0f38db       RM   Vdq Wdq -   -   VAESIMC             F=AESNI,AVX
-VEX.66.L0.0f38dc       RVM  Vdq Hdq Wdq -   VAESENC             F=AESNI,AVX
-VEX.66.L0.0f38dd       RVM  Vdq Hdq Wdq -   VAESENCLAST         F=AESNI,AVX
-VEX.66.L0.0f38de       RVM  Vdq Hdq Wdq -   VAESDEC             F=AESNI,AVX
-VEX.66.L0.0f38df       RVM  Vdq Hdq Wdq -   VAESDECLAST         F=AESNI,AVX
+# 256-bit encodings require VAES.
+VEX.66.L0.0f38dc       RVM  Vx  Hx  Wx  -   VAESENC             F=AESNI,AVX
+VEX.66.L1.0f38dc       RVM  Vx  Hx  Wx  -   VAESENC             F=AESNI,VAES,AVX
+VEX.66.L0.0f38dd       RVM  Vx  Hx  Wx  -   VAESENCLAST         F=AESNI,AVX
+VEX.66.L1.0f38dd       RVM  Vx  Hx  Wx  -   VAESENCLAST         F=AESNI,VAES,AVX
+VEX.66.L0.0f38de       RVM  Vx  Hx  Wx  -   VAESDEC             F=AESNI,AVX
+VEX.66.L1.0f38de       RVM  Vx  Hx  Wx  -   VAESDEC             F=AESNI,VAES,AVX
+VEX.66.L0.0f38df       RVM  Vx  Hx  Wx  -   VAESDECLAST         F=AESNI,AVX
+VEX.66.L1.0f38df       RVM  Vx  Hx  Wx  -   VAESDECLAST         F=AESNI,VAES,AVX
 VEX.66.L0.0f3adf       RMI  Vdq Wdq Ib  -   VAESKEYGENASSIST    F=AESNI,AVX
 #
 # AVX