diff --git a/compiler/ogwasm.pas b/compiler/ogwasm.pas
index 85bf16a1a9..0ba05145a6 100644
--- a/compiler/ogwasm.pas
+++ b/compiler/ogwasm.pas
@@ -4928,15 +4928,11 @@ implementation
             end;
         end;
 
-      const
-        DefaultMaxMemoryForThreads = 33554432;
       var
         cust_sec: TWasmCustomSectionType;
       begin
         result:=false;
         FMaxMemoryPages:=align(maxheapsize,WasmPageSize) div WasmPageSize;
-        if (ts_wasm_threads in current_settings.targetswitches) and (FMaxMemoryPages<=0) then
-          FMaxMemoryPages:=align(DefaultMaxMemoryForThreads,WasmPageSize) div WasmPageSize;
 
         { each custom sections starts with its name }
         for cust_sec in TWasmCustomSectionType do
diff --git a/compiler/parser.pas b/compiler/parser.pas
index a517fa4336..eee5fd7e75 100644
--- a/compiler/parser.pas
+++ b/compiler/parser.pas
@@ -199,6 +199,13 @@ implementation
                if heapsize=0 then
                  heapsize:=65536;
              end;
+           system_wasm32_wasi:
+             begin
+               if ts_wasm_threads in init_settings.targetswitches then
+                 maxheapsize:=33554432
+               else
+                 maxheapsize:=0;
+             end;
 {$ifdef i8086}
            system_i8086_embedded:
              begin
diff --git a/compiler/systems/t_wasi.pas b/compiler/systems/t_wasi.pas
index 2ea216d186..61f15399d5 100644
--- a/compiler/systems/t_wasi.pas
+++ b/compiler/systems/t_wasi.pas
@@ -129,7 +129,6 @@ end;
 function tlinkerwasi.MakeExecutable:boolean;
 const
   PageSize = 65536;
-  DefaultMaxMemoryForThreads = 33554432;
 var
   GCSectionsStr  : ansistring;
   binstr, cmdstr : Tcmdstr;
@@ -179,8 +178,6 @@ begin
   if ts_wasm_threads in current_settings.targetswitches then
     begin
       cmdstr := cmdstr + ' --import-memory --shared-memory --global-base=1024';
-      if maxmem<=0 then
-        maxmem:=align(DefaultMaxMemoryForThreads,PageSize);
     end;
 
   if initialmem>0 then