diff --git a/rtl/wasi/sysheap.inc b/rtl/wasi/sysheap.inc
index a3fc83f841..104043305d 100644
--- a/rtl/wasi/sysheap.inc
+++ b/rtl/wasi/sysheap.inc
@@ -22,8 +22,11 @@
 
 function SysOSAlloc(size: ptruint): pointer;
 begin
+  DebugWriteLn('SysOSAlloc');
+  SysOSAlloc:=nil;
 end;
 
 procedure SysOSFree(p: pointer; size: ptruint);
 begin
+  DebugWriteLn('SysOSFree');
 end;
diff --git a/rtl/wasi/system.pp b/rtl/wasi/system.pp
index 0f761ddc7d..7881039d66 100644
--- a/rtl/wasi/system.pp
+++ b/rtl/wasi/system.pp
@@ -171,5 +171,7 @@ begin
   { To be set if this is a library and not a program  }
   IsLibrary := FALSE;
 {$endif def FPC_HAS_FEATURE_DYNLIBS}
+  { Setup heap }
+  InitHeap;
   DebugWriteLn('System unit initialization end');
 end.