diff --git a/codeOptimizers/src/prog8/optimizer/ExpressionSimplifier.kt b/codeOptimizers/src/prog8/optimizer/ExpressionSimplifier.kt
index 0f3433304..3244ffac5 100644
--- a/codeOptimizers/src/prog8/optimizer/ExpressionSimplifier.kt
+++ b/codeOptimizers/src/prog8/optimizer/ExpressionSimplifier.kt
@@ -402,12 +402,24 @@ class ExpressionSimplifier(private val program: Program,
                     return expr.left
                 }
             }
+            else if(expr.operator=="or" && rightB.operator=="or") {
+                if(expr.left isSameAs rightB.left || expr.left isSameAs rightB.right) {
+                    // a or (a or b) -> a or b
+                    return expr.right
+                }
+            }
+            else if(expr.operator=="and" && rightB.operator=="and") {
+                if(expr.left isSameAs rightB.left || expr.left isSameAs rightB.right) {
+                    // a and (a and b) -> a and b
+                    return expr.right
+                }
+            }
         }
         val leftB = expr.left as? BinaryExpression
         if(leftB!=null) {
             // absorption laws:  (a and b) or a --> a,  (a or b) and a --> a
             if(expr.operator=="or" && leftB.operator=="and") {
-                if(expr.right isSameAs leftB.left || expr.left isSameAs leftB.right) {
+                if(expr.right isSameAs leftB.left || expr.right isSameAs leftB.right) {
                     return expr.right
                 }
             }
@@ -416,6 +428,18 @@ class ExpressionSimplifier(private val program: Program,
                     return expr.right
                 }
             }
+            else if(expr.operator=="or" && leftB.operator=="or") {
+                if(expr.right isSameAs leftB.left || expr.right isSameAs leftB.right) {
+                    // (a or b) or a -> a or b
+                    return expr.left
+                }
+            }
+            else if(expr.operator=="and" && leftB.operator=="and") {
+                if(expr.right isSameAs leftB.left || expr.right isSameAs leftB.right) {
+                    // (a and b) or a -> a and b
+                    return expr.left
+                }
+            }
         }
         return null
     }
diff --git a/compiler/test/TestOptimization.kt b/compiler/test/TestOptimization.kt
index 0eee90082..e83173f0d 100644
--- a/compiler/test/TestOptimization.kt
+++ b/compiler/test/TestOptimization.kt
@@ -825,16 +825,19 @@ main {
         if a and (b or a)
             cx16.r0 ++
 
-        ; no opt:
         if a and (b and a)
             cx16.r0 ++
         if a or (b or a)
             cx16.r0 ++
+        if (b and a) and b
+            cx16.r0 ++
+        if (b or a) or b
+            cx16.r0 ++
     }
 }"""
         val result = compileText(Cx16Target(), true, src, writeAssembly = false)!!
         val st = result.compilerAst.entrypoint.statements
-        st.size shouldBe 10
+        st.size shouldBe 12
         val if1 = st[4] as IfElse
         val if2 = st[5] as IfElse
         val if3 = st[6] as IfElse
@@ -845,8 +848,20 @@ main {
         (if4.condition as IdentifierReference).nameInSource shouldBe listOf("a")
         val if5 = st[8] as IfElse
         val if6 = st[9] as IfElse
-        if5.condition shouldBe instanceOf<BinaryExpression>()
-        if6.condition shouldBe instanceOf<BinaryExpression>()
+        val if7 = st[10] as IfElse
+        val if8 = st[11] as IfElse
+        val if5bc = if5.condition as BinaryExpression
+        val if6bc = if6.condition as BinaryExpression
+        val if7bc = if7.condition as BinaryExpression
+        val if8bc = if8.condition as BinaryExpression
+        if5bc.left shouldBe instanceOf<IdentifierReference>()
+        if5bc.right shouldBe instanceOf<IdentifierReference>()
+        if6bc.left shouldBe instanceOf<IdentifierReference>()
+        if6bc.right shouldBe instanceOf<IdentifierReference>()
+        if7bc.left shouldBe instanceOf<IdentifierReference>()
+        if7bc.right shouldBe instanceOf<IdentifierReference>()
+        if8bc.left shouldBe instanceOf<IdentifierReference>()
+        if8bc.right shouldBe instanceOf<IdentifierReference>()
     }
 
     test("funky bitshifts") {