diff --git a/src/passes/OptimizeInstructions.cpp b/src/passes/OptimizeInstructions.cpp
index 4478a7bdd3f..729a42adafb 100644
--- a/src/passes/OptimizeInstructions.cpp
+++ b/src/passes/OptimizeInstructions.cpp
@@ -1312,6 +1312,8 @@ struct OptimizeInstructions
                    !EffectAnalyzer(getPassOptions(), binary->left)
                       .hasSideEffects()) {
           return binary->right;
+        } else if (binary->op == EqInt64) {
+          return Builder(*getModule()).makeUnary(EqZInt64, binary->left);
         }
       }
       // operations on all 1s
diff --git a/test/passes/O.bin.txt b/test/passes/O.bin.txt
index 89a24046c75..7af8de37e31 100644
--- a/test/passes/O.bin.txt
+++ b/test/passes/O.bin.txt
@@ -7,9 +7,8 @@
  (export "fac-opt" (func $4))
  (func $0 (; 0 ;) (; has Stack IR ;) (type $0) (param $0 i64) (result i64)
   (if (result i64)
-   (i64.eq
+   (i64.eqz
     (local.get $0)
-    (i64.const 0)
    )
    (i64.const 1)
    (i64.mul
@@ -25,9 +24,8 @@
  )
  (func $1 (; 1 ;) (; has Stack IR ;) (type $0) (param $0 i64) (result i64)
   (if (result i64)
-   (i64.eq
+   (i64.eqz
     (local.get $0)
-    (i64.const 0)
    )
    (i64.const 1)
    (i64.mul
@@ -51,9 +49,10 @@
   )
   (loop $label$3
    (if
-    (i64.ne
-     (local.get $0)
-     (i64.const 0)
+    (i32.eqz
+     (i64.eqz
+      (local.get $0)
+     )
     )
     (block
      (local.set $1
diff --git a/test/passes/optimize-instructions_enable-threads.txt b/test/passes/optimize-instructions_enable-threads.txt
index f54b6ae991c..ef3122a8983 100644
--- a/test/passes/optimize-instructions_enable-threads.txt
+++ b/test/passes/optimize-instructions_enable-threads.txt
@@ -196,6 +196,22 @@
     (i32.const 0)
    )
   )
+  (drop
+   (i64.eqz
+    (i64.const 100)
+   )
+  )
+  (drop
+   (i64.eq
+    (i64.const 0)
+    (i64.const 100)
+   )
+  )
+  (drop
+   (i64.eqz
+    (i64.const 0)
+   )
+  )
   (if
    (i32.const 123)
    (nop)
diff --git a/test/passes/optimize-instructions_enable-threads.wast b/test/passes/optimize-instructions_enable-threads.wast
index dfcaea5976a..243cb79d758 100644
--- a/test/passes/optimize-instructions_enable-threads.wast
+++ b/test/passes/optimize-instructions_enable-threads.wast
@@ -212,6 +212,24 @@
         (i32.const 0)
       )
     )
+    (drop
+      (i64.eq
+        (i64.const 100)
+        (i64.const 0)
+      )
+    )
+    (drop
+      (i64.eq
+        (i64.const 0)
+        (i64.const 100)
+      )
+    )
+    (drop
+      (i64.eq
+        (i64.const 0)
+        (i64.const 0)
+      )
+    )
     (if
       (i32.eqz
         (i32.eqz