diff --git a/doc-collection/opcodes/x86/8086.dop b/doc-collection/opcodes/x86/8086.dop
index 81990f6d3..d4b51c260 100644
--- a/doc-collection/opcodes/x86/8086.dop
+++ b/doc-collection/opcodes/x86/8086.dop
@@ -491,4 +491,24 @@ opcode sequence(0xA7) name "CMPSW" {
 }
 opcode sequence(0xA8 immb) name "TEST" { common opcode "TEST" param(AL,immb); }
 opcode sequence(0xA9 immw) name "TEST" { common opcode "TEST" param(accum,immw); }
+opcode sequence(0xAA) name "STOSB" {
+    /* if DF = 1, dstidx -= 1; */
+    /* if DF = 0, dstidx += 1; */
+    input AL;
+    output memory reference byte farptr(ES,dstidx);
+    modifies dstidx;
+
+    /* how to show it */
+    syntax ;
+}
+opcode sequence(0xAB) name "STOSW" {
+    /* if DF = 1, dstidx -= wordsize; */
+    /* if DF = 0, dstidx += wordsize; */
+    input accum;
+    output memory reference word farptr(ES,dstidx);
+    modifies dstidx;
+
+    /* how to show it */
+    syntax ;
+}