diff --git a/codeOptimizers/src/prog8/optimizer/ExpressionSimplifier.kt b/codeOptimizers/src/prog8/optimizer/ExpressionSimplifier.kt
index 8430b9542..0d4799758 100644
--- a/codeOptimizers/src/prog8/optimizer/ExpressionSimplifier.kt
+++ b/codeOptimizers/src/prog8/optimizer/ExpressionSimplifier.kt
@@ -187,12 +187,37 @@ class ExpressionSimplifier(private val program: Program,
             }
         }
 
+        // X <= Y-1 ---> X<Y  ,  X >= Y+1 ---> X>Y
+        if(leftDt in IntegerDatatypes && rightDt in IntegerDatatypes) {
+            val rightExpr = expr.right as? BinaryExpression
+            if(rightExpr!=null && rightExpr.right.constValue(program)?.number==1.0) {
+                if (expr.operator == "<=" && rightExpr.operator == "-") {
+                    expr.operator = "<"
+                    return listOf(IAstModification.ReplaceNode(rightExpr, rightExpr.left, expr))
+                } else if (expr.operator == ">=" && rightExpr.operator == "+") {
+                    expr.operator = ">"
+                    return listOf(IAstModification.ReplaceNode(rightExpr, rightExpr.left, expr))
+                }
+            }
+        }
+
         if(leftDt!=DataType.FLOAT && expr.operator == ">=" && rightVal?.number == 1.0) {
             // for integers: x >= 1  -->  x > 0
             expr.operator = ">"
             return listOf(IAstModification.ReplaceNode(expr.right, NumericLiteral.optimalInteger(0, expr.right.position), expr))
         }
 
+        // for signed integers: X <= -1 => X<0 ,  X > -1 => X>=0
+        if(leftDt in SignedDatatypes && leftDt!=DataType.FLOAT && rightVal?.number==-1.0) {
+            if(expr.operator=="<=") {
+                expr.operator = "<"
+                return listOf(IAstModification.ReplaceNode(expr.right, NumericLiteral(rightDt, 0.0, expr.right.position), expr))
+            } else if(expr.operator==">") {
+                expr.operator = ">="
+                return listOf(IAstModification.ReplaceNode(expr.right, NumericLiteral(rightDt, 0.0, expr.right.position), expr))
+            }
+        }
+
         if (leftDt == DataType.UBYTE || leftDt == DataType.UWORD) {
             if(expr.operator == ">=" && rightVal?.number == 0.0) {
                 // unsigned >= 0 --> true
diff --git a/docs/source/todo.rst b/docs/source/todo.rst
index 7e495acfa..8e0499d74 100644
--- a/docs/source/todo.rst
+++ b/docs/source/todo.rst
@@ -3,13 +3,6 @@ TODO
 
 For next minor release
 ^^^^^^^^^^^^^^^^^^^^^^
-- add optimizations for integer X <= Y-1 ---> X<Y   , X >= Y+1 ---> X>Y
-- add optimizations for integer:
-    X >= 1  =>  X > 0     (signed and unsigned)
-    X < 1   =>  X <= 0      (signed)    or  X==0   (unsigned)
-    X <= -1 =>  X >= 0      (signed only)
-    X > -1  =>  X >= 0      (signed only)
-
 ...