diff --git a/codeOptimizers/src/prog8/optimizer/Inliner.kt b/codeOptimizers/src/prog8/optimizer/Inliner.kt
index 122444345..d8d90b44e 100644
--- a/codeOptimizers/src/prog8/optimizer/Inliner.kt
+++ b/codeOptimizers/src/prog8/optimizer/Inliner.kt
@@ -118,9 +118,11 @@ class Inliner(val program: Program): AstWalker() {
         }
 
         private fun makeFullyScoped(identifier: IdentifierReference) {
-            val scoped = (identifier.targetStatement(program)!! as INamedStatement).scopedName
-            val scopedIdent = IdentifierReference(scoped, identifier.position)
-            modifications += IAstModification.ReplaceNode(identifier, scopedIdent, identifier.parent)
+            identifier.targetStatement(program)?.let { target ->
+                val scoped = (target as INamedStatement).scopedName
+                val scopedIdent = IdentifierReference(scoped, identifier.position)
+                modifications += IAstModification.ReplaceNode(identifier, scopedIdent, identifier.parent)
+            }
         }
 
         private fun makeFullyScoped(call: BuiltinFunctionCallStatement) {
@@ -130,27 +132,30 @@ class Inliner(val program: Program): AstWalker() {
         }
 
         private fun makeFullyScoped(call: FunctionCallStatement) {
-            val sub = call.target.targetSubroutine(program)!!
-            val scopedName = IdentifierReference(sub.scopedName, call.target.position)
-            val scopedArgs = makeScopedArgs(call.args)
-            val scopedCall = FunctionCallStatement(scopedName, scopedArgs.toMutableList(), call.void, call.position)
-            modifications += IAstModification.ReplaceNode(call, scopedCall, call.parent)
+            call.target.targetSubroutine(program)?.let { sub ->
+                val scopedName = IdentifierReference(sub.scopedName, call.target.position)
+                val scopedArgs = makeScopedArgs(call.args)
+                val scopedCall = FunctionCallStatement(scopedName, scopedArgs.toMutableList(), call.void, call.position)
+                modifications += IAstModification.ReplaceNode(call, scopedCall, call.parent)
+            }
         }
 
         private fun makeFullyScoped(call: BuiltinFunctionCall) {
-            val sub = call.target.targetSubroutine(program)!!
-            val scopedName = IdentifierReference(sub.scopedName, call.target.position)
-            val scopedArgs = makeScopedArgs(call.args)
-            val scopedCall = BuiltinFunctionCall(scopedName, scopedArgs.toMutableList(), call.position)
-            modifications += IAstModification.ReplaceNode(call, scopedCall, call.parent)
+            call.target.targetSubroutine(program)?.let { sub ->
+                val scopedName = IdentifierReference(sub.scopedName, call.target.position)
+                val scopedArgs = makeScopedArgs(call.args)
+                val scopedCall = BuiltinFunctionCall(scopedName, scopedArgs.toMutableList(), call.position)
+                modifications += IAstModification.ReplaceNode(call, scopedCall, call.parent)
+            }
         }
 
         private fun makeFullyScoped(call: FunctionCallExpression) {
-            val sub = call.target.targetSubroutine(program)!!
-            val scopedName = IdentifierReference(sub.scopedName, call.target.position)
-            val scopedArgs = makeScopedArgs(call.args)
-            val scopedCall = FunctionCallExpression(scopedName, scopedArgs.toMutableList(), call.position)
-            modifications += IAstModification.ReplaceNode(call, scopedCall, call.parent)
+            call.target.targetSubroutine(program)?.let { sub ->
+                val scopedName = IdentifierReference(sub.scopedName, call.target.position)
+                val scopedArgs = makeScopedArgs(call.args)
+                val scopedCall = FunctionCallExpression(scopedName, scopedArgs.toMutableList(), call.position)
+                modifications += IAstModification.ReplaceNode(call, scopedCall, call.parent)
+            }
         }
 
         private fun makeScopedArgs(args: List<Expression>): List<Expression> {
diff --git a/compiler/test/TestOptimization.kt b/compiler/test/TestOptimization.kt
index 56501d232..81303b036 100644
--- a/compiler/test/TestOptimization.kt
+++ b/compiler/test/TestOptimization.kt
@@ -793,4 +793,16 @@ main {
         (statements[6] as Assignment).target.memoryAddress!!.addressExpression.constValue(result.program)!!.number shouldBe 53281.0
         (statements[7] as Assignment).target.memoryAddress!!.addressExpression.constValue(result.program)!!.number shouldBe 53281.0
     }
+
+    test("no crash on sorting unused array") {
+        val text="""
+main {
+	ubyte[5] cards = [ 14, 6, 29, 16, 3 ]
+
+	sub start() {
+	    sort(cards)
+	}
+}"""
+        compileText(C64Target(), true, text, writeAssembly = false) shouldNotBe null
+    }
 })