diff --git a/rtl/zxspectrum/sysheap.inc b/rtl/zxspectrum/sysheap.inc
index d2d7059a0f..5d2e097257 100644
--- a/rtl/zxspectrum/sysheap.inc
+++ b/rtl/zxspectrum/sysheap.inc
@@ -13,3 +13,14 @@
 
  **********************************************************************}
 
+{*****************************************************************************
+                              Heap Management
+*****************************************************************************}
+
+function SysOSAlloc (size: ptruint): pointer;
+begin
+end;
+
+procedure SysOSFree(p: pointer; size: ptruint);
+begin
+end;
diff --git a/rtl/zxspectrum/system.pp b/rtl/zxspectrum/system.pp
index ddb87152ac..50c8de0cfd 100644
--- a/rtl/zxspectrum/system.pp
+++ b/rtl/zxspectrum/system.pp
@@ -6,7 +6,14 @@ interface
 
 {$define FPC_IS_SYSTEM}
 
+{ The heap for ZX Spectrum is implemented
+  in tinyheap.inc include file,
+  but it uses default SysGetMem names }
+
+{$define HAS_MEMORYMANAGER}
+
 {$I systemh.inc}
+{$I tnyheaph.inc}
 
 {$ifndef FPUNONE}
 {$ifdef FPC_HAS_FEATURE_SOFTFPU}
@@ -104,6 +111,7 @@ implementation
 {$ifdef FULL_RTL}
 
 {$I system.inc}
+{$I tinyheap.inc}
 
 {$ifndef FPUNONE}
 {$ifdef FPC_HAS_FEATURE_SOFTFPU}