diff --git a/common/h/registers/x86_regs.h b/common/h/registers/x86_regs.h
index 4c44345b43..8f98da033d 100644
--- a/common/h/registers/x86_regs.h
+++ b/common/h/registers/x86_regs.h
@@ -61,7 +61,7 @@ namespace Dyninst { namespace x86 {
   const signed int W_REG  = 0x00000400;  // 16-bit, first word
   const signed int FPDBL  = 0x00000500;  // 80-bit x87 FPU
   const signed int MMS    = 0x00000600;  // 64-bit MMX and 3DNow!
-  const signed int OCT    = 0x00000700;  // 128-bit SSE, FC16, XOP, AVX, and FMA3/4
+  const signed int XMMS   = 0x00000700;  // 128-bit SSE, FC16, XOP, AVX, and FMA3/4
   const signed int YMMS   = 0x00000800;  // 256-bit SSE, AVX2, FMA3/4
   const signed int ZMMS   = 0x00000900;  // 512-bit AVX-512/AVX10
   const signed int KMSKS  = 0x00000A00;  // 64-bit mask from AVX-512/AVX10
@@ -200,14 +200,14 @@ namespace Dyninst { namespace x86 {
   DEF_REGISTER(        k6,   0x06 | KMSKS | KMASK | Arch_x86, "x86");
   DEF_REGISTER(        k7,   0x07 | KMSKS | KMASK | Arch_x86, "x86");
 
-  DEF_REGISTER(      xmm0,   0x00 |   OCT |   XMM | Arch_x86, "x86");
-  DEF_REGISTER(      xmm1,   0x01 |   OCT |   XMM | Arch_x86, "x86");
-  DEF_REGISTER(      xmm2,   0x02 |   OCT |   XMM | Arch_x86, "x86");
-  DEF_REGISTER(      xmm3,   0x03 |   OCT |   XMM | Arch_x86, "x86");
-  DEF_REGISTER(      xmm4,   0x04 |   OCT |   XMM | Arch_x86, "x86");
-  DEF_REGISTER(      xmm5,   0x05 |   OCT |   XMM | Arch_x86, "x86");
-  DEF_REGISTER(      xmm6,   0x06 |   OCT |   XMM | Arch_x86, "x86");
-  DEF_REGISTER(      xmm7,   0x07 |   OCT |   XMM | Arch_x86, "x86");
+  DEF_REGISTER(      xmm0,   0x00 |  XMMS |   XMM | Arch_x86, "x86");
+  DEF_REGISTER(      xmm1,   0x01 |  XMMS |   XMM | Arch_x86, "x86");
+  DEF_REGISTER(      xmm2,   0x02 |  XMMS |   XMM | Arch_x86, "x86");
+  DEF_REGISTER(      xmm3,   0x03 |  XMMS |   XMM | Arch_x86, "x86");
+  DEF_REGISTER(      xmm4,   0x04 |  XMMS |   XMM | Arch_x86, "x86");
+  DEF_REGISTER(      xmm5,   0x05 |  XMMS |   XMM | Arch_x86, "x86");
+  DEF_REGISTER(      xmm6,   0x06 |  XMMS |   XMM | Arch_x86, "x86");
+  DEF_REGISTER(      xmm7,   0x07 |  XMMS |   XMM | Arch_x86, "x86");
 
   DEF_REGISTER(      ymm0,   0x00 |  YMMS |   YMM | Arch_x86, "x86");
   DEF_REGISTER(      ymm1,   0x01 |  YMMS |   YMM | Arch_x86, "x86");
diff --git a/common/src/registers/MachRegister.C b/common/src/registers/MachRegister.C
index 6947d7bd46..773e3d55e5 100644
--- a/common/src/registers/MachRegister.C
+++ b/common/src/registers/MachRegister.C
@@ -125,7 +125,7 @@ namespace Dyninst {
             // is defined with this size type
             // case x86::QUAD:
             //   return 8;
-          case x86::OCT: return 16;
+          case x86::XMMS: return 16;
           case x86::FPDBL: return 10;
           case x86::BIT: return 0;
           case x86::YMMS: return 32;
@@ -976,7 +976,7 @@ namespace Dyninst {
     switch(getArchitecture()) {
       case Arch_x86:
         switch(subrange) {
-          case x86::OCT:
+          case x86::XMMS:
           case x86::KMSKS:
           case x86::FPDBL: p = x86_regpos_qword; break;
           case x86::MMS: p = x86_regpos_qword; break;
@@ -995,7 +995,7 @@ namespace Dyninst {
       case Arch_x86_64:
         switch(subrange) {
           case x86::FULL:
-          case x86::OCT:
+          case x86::XMMS:
           case x86::FPDBL: p = x86_regpos_qword; break;
           case x86::H_REG: p = x86_regpos_high_byte; break;
           case x86::L_REG: p = x86_regpos_low_byte; break;