diff --git a/compiler/src/prog8/compiler/astprocessing/AstChecker.kt b/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
index 7f872fdff..8a8bb470b 100644
--- a/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
+++ b/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
@@ -2093,7 +2093,9 @@ internal class AstChecker(private val program: Program,
     }
 
     override fun visit(memread: DirectMemoryRead) {
-        if(!allowedMemoryAccessAddressExpression(memread.addressExpression, program))
+        if(memread.addressExpression.inferType(program).isLong)
+            errors.err("long address not yet supported", memread.addressExpression.position)
+        else if(!allowedMemoryAccessAddressExpression(memread.addressExpression, program))
             errors.err("invalid address type for memory access, expected ^^ubyte or just uword", memread.position)
 
         val pointervar = memread.addressExpression as? IdentifierReference
@@ -2126,7 +2128,9 @@ internal class AstChecker(private val program: Program,
     }
 
     override fun visit(memwrite: DirectMemoryWrite) {
-        if(!allowedMemoryAccessAddressExpression(memwrite.addressExpression, program))
+        if(memwrite.addressExpression.inferType(program).isLong)
+            errors.err("long address not yet supported", memwrite.addressExpression.position)
+        else if(!allowedMemoryAccessAddressExpression(memwrite.addressExpression, program))
             errors.err("invalid address type for memory access, expected ^^ubyte or just uword", memwrite.position)
 
         val pointervar = memwrite.addressExpression as? IdentifierReference
diff --git a/compiler/src/prog8/compiler/astprocessing/TypecastsAdder.kt b/compiler/src/prog8/compiler/astprocessing/TypecastsAdder.kt
index aabbc9d64..8e861ca71 100644
--- a/compiler/src/prog8/compiler/astprocessing/TypecastsAdder.kt
+++ b/compiler/src/prog8/compiler/astprocessing/TypecastsAdder.kt
@@ -339,8 +339,13 @@ class TypecastsAdder(val program: Program, val options: CompilationOptions, val
     }
 
     override fun after(memread: DirectMemoryRead, parent: Node): Iterable<IAstModification> {
-        // make sure the memory address is an uword or a pointer (to whatever type), otherwise cast
+        // make sure the memory address is an uword or long or a pointer (to whatever type), otherwise cast
         val dt = memread.addressExpression.inferType(program).getOr(DataType.UWORD)
+        if(dt.isLong) {
+            val constAddr = memread.addressExpression.constValue(program)?.number
+            if(constAddr==null || constAddr>=65536)
+                return noModifications
+        }
         if(dt.isUndefined || dt.isUnsignedWord || dt.isPointer)
             return noModifications
 
@@ -354,8 +359,13 @@ class TypecastsAdder(val program: Program, val options: CompilationOptions, val
     }
 
     override fun after(memwrite: DirectMemoryWrite, parent: Node): Iterable<IAstModification> {
-        // make sure the memory address is an uword or a pointer (to whatever type), otherwise cast
+        // make sure the memory address is an uword or long or a pointer (to whatever type), otherwise cast
         val dt = memwrite.addressExpression.inferType(program).getOr(DataType.UWORD)
+        if(dt.isLong) {
+            val constAddr = memwrite.addressExpression.constValue(program)?.number
+            if(constAddr==null || constAddr>=65536)
+                return noModifications
+        }
         if(dt.isUndefined || dt.isUnsignedWord || dt.isPointer)
             return noModifications
 
diff --git a/compiler/test/TestMemory.kt b/compiler/test/TestMemory.kt
index 5a3125bd0..f2592fead 100644
--- a/compiler/test/TestMemory.kt
+++ b/compiler/test/TestMemory.kt
@@ -16,10 +16,7 @@ import prog8.ast.expressions.PrefixExpression
 import prog8.ast.statements.*
 import prog8.code.core.*
 import prog8.code.source.SourceCode
-import prog8.code.target.C128Target
-import prog8.code.target.C64Target
-import prog8.code.target.PETTarget
-import prog8.code.target.VMTarget
+import prog8.code.target.*
 import prog8tests.helpers.*
 
 
@@ -438,4 +435,24 @@ main {
         errors.errors[0] shouldContain "8:9: cannot assign to an array or string that is located in ROM"
         errors.errors[1] shouldContain "9:9: cannot assign to an array or string that is located in ROM"
     }
+
+    test("long addresses not yet supported in memread and memwrite") {
+        val src = """
+main {
+    sub start() {
+        const long bufferll = 888888
+        long @shared addrlv = 777777
+
+        cx16.r0L = bufferll[2]
+        cx16.r1L = @(999999)
+        cx16.r2L = @(addrlv)
+    }
+}"""
+        val errors = ErrorReporterForTests()
+        compileText(Cx16Target(), true, src, outputDir, errors = errors, writeAssembly = false) shouldBe null
+        errors.errors.size shouldBe 3
+        errors.errors[0] shouldContain "long address not yet supported"
+        errors.errors[1] shouldContain "long address not yet supported"
+        errors.errors[2] shouldContain "long address not yet supported"
+    }
 })