diff --git a/constants.lua b/constants.lua
index d7e72f2..fa7b02a 100644
--- a/constants.lua
+++ b/constants.lua
@@ -66,12 +66,12 @@ constants.opcodes = {
     OP_I32_NE           = 0x47,
     OP_I32_LT_S         = 0x48,
     OP_I32_LT_U         = 0x49,
-    OP_I32_GT_S         = 0x50,
-    OP_I32_GT_U         = 0x51,
-    OP_I32_LE_S         = 0x52,
-    OP_I32_LE_U         = 0x53,
-    OP_I32_GE_S         = 0x54,
-    OP_I32_GE_U         = 0x55,
+    OP_I32_GT_S         = 0x4A,
+    OP_I32_GT_U         = 0x4B,
+    OP_I32_LE_S         = 0x4C,
+    OP_I32_LE_U         = 0x4D,
+    OP_I32_GE_S         = 0x4E,
+    OP_I32_GE_U         = 0x4F,
 --   i64 comparisons
     OP_I64_EQZ          = 0x50,
     OP_I64_EQ           = 0x51,
@@ -321,6 +321,8 @@ constants.ilengths = {
     [c.OP_I32_GT_U]         = 1,
     [c.OP_I32_LE_S]         = 1,
     [c.OP_I32_LE_U]         = 1,
+    [c.OP_I32_GE_S]         = 1,
+    [c.OP_I32_GE_U]         = 1,
 -- i64 comparisons
     [c.OP_I64_EQZ]          = 1,
     [c.OP_I64_EQ]           = 1,
diff --git a/wasmlib.lua b/wasmlib.lua
index 0b4de4f..62b34b7 100644
--- a/wasmlib.lua
+++ b/wasmlib.lua
@@ -8,6 +8,10 @@ local intutil = require("intutil")
 local fileutil = require("fileutil")
 local strutil = require("strutil")
 
+local function trace(...)
+    if wasmlib.TRACING then print(...) end
+end
+
 wasmlib.VM = {
     numImportedFuncs = 0,
     stack = {},
@@ -332,7 +336,7 @@ local function findMatchingEndOrElse(body, i, depth)
         local length = constants.ilengths[opcode]
         if length == 0 then
             if constants.blockOpcodes[opcode] ~= nil then
-                i = findMatchingEndOrElse(body, i + 1, depth + 1) + (depth > 0 and 1 or 0)
+                i = findMatchingEndOrElse(body, i + 2, depth + 1) + (depth > 0 and 1 or 0)
             elseif opcode == constants.opcodes.OP_ELSE then
                 i = i + 1
             end
@@ -422,6 +426,8 @@ function wasmlib.VM:step()
     end
 
     local opcode = self:nextArg()
+    trace(self:curFrame().pc,opcode,"###",table.unpack(self.stack))
+    trace(#self.labelStack,"---",table.unpack(self.labelStack))
 
     local c = constants.opcodes
     local optable = {