diff --git a/encode.c b/encode.c
index 106d2e8..24c5d4d 100644
--- a/encode.c
+++ b/encode.c
@@ -322,7 +322,7 @@ fe_enc64_impl(uint8_t** restrict buf, uint64_t mnem, FeOp op0, FeOp op1,
         const struct EncodeDesc* desc = &descs[desc_idx];
         const struct EncodingInfo* ei = &encoding_infos[desc->enc];
         uint64_t opc = desc->opc;
-        int64_t imm;
+        int64_t imm = 0xcc;
 
         if (UNLIKELY(desc->enc == ENC_INVALID)) goto fail;
 
@@ -349,14 +349,17 @@ fe_enc64_impl(uint8_t** restrict buf, uint64_t mnem, FeOp op0, FeOp op1,
         if (UNLIKELY(mnem & FE_SEG_MASK))
             opc |= (mnem & FE_SEG_MASK) << (OPC_SEG_IDX - 16);
 
-        if (ei->immctl && ei->immctl != 3)
+        if (ei->immctl > 0) {
             imm = ops[ei->immidx];
-        if (ei->immctl == 6) {
-            if (UNLIKELY(mnem & FE_JMPL) && desc->alt) goto next;
-            imm -= (int64_t) *buf + opc_size(opc) + desc->immsz;
+            if (ei->immctl == 3)
+                imm = op_reg_idx(imm) << 4;
+            if (ei->immctl == 6) {
+                if (UNLIKELY(mnem & FE_JMPL) && desc->alt) goto next;
+                imm -= (int64_t) *buf + opc_size(opc) + desc->immsz;
+            }
+            if (UNLIKELY(ei->immctl == 1) && imm != 1) goto next;
+            if (ei->immctl >= 4 && !op_imm_n(imm, desc->immsz)) goto next;
         }
-        if (UNLIKELY(ei->immctl == 1) && imm != 1) goto next;
-        if (ei->immctl >= 2 && !op_imm_n(imm, desc->immsz)) goto next;
 
         // NOP has no operands, so this must be the 32-bit OA XCHG
         if ((desc->opc & ~7) == 0x90 && ops[0] == FE_AX) goto next;
diff --git a/parseinstrs.py b/parseinstrs.py
index 962c17b..a62f3b3 100644
--- a/parseinstrs.py
+++ b/parseinstrs.py
@@ -128,8 +128,10 @@ class InstrDesc(NamedTuple):
 
     def imm_size(self, opsz):
         flags = ENCODINGS[self.encoding]
-        if flags.imm_control < 4:
+        if flags.imm_control < 3:
             return 0
+        if flags.imm_control == 3:
+            return 1
         if self.mnemonic == "ENTER":
             return 3
         if "IMM_8" in self.flags:
diff --git a/tests/test_encode.c b/tests/test_encode.c
index dce7233..26eef16 100644
--- a/tests/test_encode.c
+++ b/tests/test_encode.c
@@ -160,6 +160,12 @@ main(int argc, char** argv)
     TEST("\xc4\xe2\x71\x9d\xc2", FE_VFNMADD132SSrrr, FE_XMM0, FE_XMM1, FE_XMM2);
     TEST("\xc4\xe2\xf1\x9d\xc2", FE_VFNMADD132SDrrr, FE_XMM0, FE_XMM1, FE_XMM2);
 
+    // Test RVMR encoding
+    TEST("\xc4\xe3\x71\x4a\xc2\x30", FE_VBLENDVPS128rrrr, FE_XMM0, FE_XMM1, FE_XMM2, FE_XMM3);
+    TEST("\xc4\xe3\x75\x4a\xc2\x30", FE_VBLENDVPS256rrrr, FE_XMM0, FE_XMM1, FE_XMM2, FE_XMM3);
+    TEST("\xc4\xe3\x71\x4a\x05\x00\x00\x00\x00\x20", FE_VBLENDVPS128rrmr, FE_XMM0, FE_XMM1, FE_MEM(FE_IP, 0, 0, 10), FE_XMM2);
+    TEST("\xc4\xe3\x75\x4a\x05\x00\x00\x00\x00\x20", FE_VBLENDVPS256rrmr, FE_XMM0, FE_XMM1, FE_MEM(FE_IP, 0, 0, 10), FE_XMM2);
+
     // VSIB encodings
     TEST("", FE_VGATHERDPS128rmr, FE_XMM0, FE_XMM0, FE_XMM1); // must have memory operand
     TEST("", FE_VGATHERDPS128rmr, FE_XMM0, FE_MEM(FE_DI, 8, 0, 0), FE_XMM1); // must have SIB