diff --git a/src/mono/browser/build/BrowserWasmApp.targets b/src/mono/browser/build/BrowserWasmApp.targets
index 484d3486c5eaa8..d75513604304c6 100644
--- a/src/mono/browser/build/BrowserWasmApp.targets
+++ b/src/mono/browser/build/BrowserWasmApp.targets
@@ -260,6 +260,8 @@
       <EmccCompileOptimizationFlag Condition="'$(EmccCompileOptimizationFlag)' == ''">$(_EmccOptimizationFlagDefault)</EmccCompileOptimizationFlag>
       <!-- FIXME: which one should take precedence? -->
       <WasmCompileOptimizationFlag>$(EmccCompileOptimizationFlag)</WasmCompileOptimizationFlag>
+      <WasmBitcodeCompileOptimizationFlag Condition="'$(WasmBitcodeCompileOptimizationFlag)' == '' and '$(Configuration)' == 'Release'">-O2</WasmBitcodeCompileOptimizationFlag>
+      <WasmBitcodeCompileOptimizationFlag Condition="'$(WasmBitcodeCompileOptimizationFlag)' == '' ">$(WasmCompileOptimizationFlag)</WasmBitcodeCompileOptimizationFlag>
       <EmccLinkOptimizationFlag    Condition="'$(EmccLinkOptimizationFlag)' == '' and '$(Configuration)' == 'Release'">-O2</EmccLinkOptimizationFlag>
       <EmccLinkOptimizationFlag    Condition="'$(EmccLinkOptimizationFlag)' == ''"   >$(WasmCompileOptimizationFlag)</EmccLinkOptimizationFlag>
       <WasmLinkOptimizationFlag>$(EmccLinkOptimizationFlag)</WasmLinkOptimizationFlag>
@@ -406,6 +408,7 @@
 
   <Target Name="_BrowserWasmBeforeWriteCompileBitcodeRsp" BeforeTargets="_WasmWriteRspForCompilingBitcode">
     <ItemGroup>
+      <_BitcodeCompileFlags Include="$(WasmBitcodeCompileOptimizationFlag)" />
       <_BitcodeCompileFlags Include="@(_EmccCommonFlags)" />
       <_BitcodeCompileFlags Include="$(EmccExtraBitcodeCompilationFlags)" />
     </ItemGroup>
diff --git a/src/mono/wasi/build/WasiApp.targets b/src/mono/wasi/build/WasiApp.targets
index c5ecf84ad0c73c..cad25a76067295 100644
--- a/src/mono/wasi/build/WasiApp.targets
+++ b/src/mono/wasi/build/WasiApp.targets
@@ -148,6 +148,8 @@
 
       <WasiClangCompileOptimizationFlag Condition="'$(WasiClangCompileOptimizationFlag)' == ''">$(_WasiClangOptimizationFlagDefault)</WasiClangCompileOptimizationFlag>
       <WasmCompileOptimizationFlag>$(WasiClangCompileOptimizationFlag)</WasmCompileOptimizationFlag>
+      <WasiBitcodeCompileOptimizationFlag Condition="'$(WasiBitcodeCompileOptimizationFlag)' == '' and '$(Configuration)' == 'Release'">-O2</WasiBitcodeCompileOptimizationFlag>
+      <WasiBitcodeCompileOptimizationFlag Condition="'$(WasiBitcodeCompileOptimizationFlag)' == ''"   >$(WasiClangCompileOptimizationFlag)</WasiBitcodeCompileOptimizationFlag>
       <WasiClangLinkOptimizationFlag    Condition="'$(WasiClangLinkOptimizationFlag)' == '' and '$(Configuration)' == 'Release'">-O2</WasiClangLinkOptimizationFlag>
       <WasiClangLinkOptimizationFlag    Condition="'$(WasiClangLinkOptimizationFlag)' == ''"   >$(WasiClangCompileOptimizationFlag)</WasiClangLinkOptimizationFlag>
       <WasmLinkOptimizationFlag>$(WasiClangLinkOptimizationFlag)</WasmLinkOptimizationFlag>
@@ -265,6 +267,7 @@
   <!-- FIXME: merge with some other target -->
   <Target Name="_WasiBeforeWriteRspForCompilingBitcodeRsp" BeforeTargets="_WasmWriteRspForCompilingBitcode">
     <ItemGroup>
+      <_BitcodeCompileFlags Include="@(WasiBitcodeCompileOptimizationFlag)" />
       <_BitcodeCompileFlags Include="@(_WasiClangCommonFlags)" />
       <_BitcodeCompileFlags Include="$(WasiClangExtraBitcodeCompileFlags)" />
     </ItemGroup>
diff --git a/src/mono/wasm/build/WasmApp.Common.targets b/src/mono/wasm/build/WasmApp.Common.targets
index f06b9a1261fe5e..e9cda6ccea50e1 100644
--- a/src/mono/wasm/build/WasmApp.Common.targets
+++ b/src/mono/wasm/build/WasmApp.Common.targets
@@ -44,6 +44,8 @@
 
       - $(EmccLinkOptimizationFlag)         - Optimization flag to use for the link step
       - $(EmccCompileOptimizationFlag)      - Optimization flag to use for compiling native files
+      - $(WasmBitcodeCompileOptimizationFlag)
+                                            - Optimization flag to use for compiling bitcode files
 
       - $(EmccFlags)                        - Emcc flags used for both compiling native files, and linking
       - $(EmccExtraLDFlags)                 - Extra emcc flags for linking