diff --git a/eng/testing/tests.browser.targets b/eng/testing/tests.browser.targets
index 6b561bdefb60c2..5b5383253c3c67 100644
--- a/eng/testing/tests.browser.targets
+++ b/eng/testing/tests.browser.targets
@@ -109,7 +109,7 @@
     <_XHarnessArgs Condition="'$(_UseWasmSymbolicator)' == 'true'" >$(_XHarnessArgs) --symbol-patterns wasm-symbol-patterns.txt</_XHarnessArgs>
     <_XHarnessArgs Condition="'$(_UseWasmSymbolicator)' == 'true'" >$(_XHarnessArgs) --symbolicator WasmSymbolicator.dll,Microsoft.WebAssembly.Internal.SymbolicatorWrapperForXHarness</_XHarnessArgs>
     <_XHarnessArgs Condition="'$(_WasmBrowserPathForTests)' != ''" >$(_XHarnessArgs) &quot;--browser-path=$(_WasmBrowserPathForTests)&quot;</_XHarnessArgs>
-    <_XHarnessArgs Condition="'$(_XHarnessTestsTimeout)' != ''   " >$(_XHarnessArgs) &quot;--timeout=$(_XHarnessTestsTimeout)&quot;</_XHarnessArgs>
+    <_XHarnessArgs Condition="'$(WasmXHarnessTestsTimeout)' != ''" >$(_XHarnessArgs) &quot;--timeout=$(WasmXHarnessTestsTimeout)&quot;</_XHarnessArgs>
     <_XHarnessArgs Condition="'$(WasmXHarnessArgsCli)' != ''"      >$(_XHarnessArgs) $(WasmXHarnessArgsCli)</_XHarnessArgs>
 
     <!-- There two flavors of WasmXHarnessArgs and WasmXHarnessMonoArgs, one is MSBuild property and the other is environment variable -->
diff --git a/eng/testing/tests.wasi.targets b/eng/testing/tests.wasi.targets
index 1841dd20ae9a01..87dbe5f5a8e595 100644
--- a/eng/testing/tests.wasi.targets
+++ b/eng/testing/tests.wasi.targets
@@ -40,7 +40,7 @@
     <_XHarnessArgs Condition="'$(WasmSingleFileBundle)' != 'true'" >$(_XHarnessArgs) --engine-arg=--dir=.</_XHarnessArgs>
     <_XHarnessArgs Condition="'$(IsFunctionalTest)' == 'true'"     >$(_XHarnessArgs) --expected-exit-code=$(ExpectedExitCode)</_XHarnessArgs>
     <_XHarnessArgs Condition="'$(WasmXHarnessArgs)' != ''"         >$(_XHarnessArgs) $(WasmXHarnessArgs)</_XHarnessArgs>
-    <_XHarnessArgs Condition="'$(_XHarnessTestsTimeout)' != ''   " >$(_XHarnessArgs) &quot;--timeout=$(_XHarnessTestsTimeout)&quot;</_XHarnessArgs>
+    <_XHarnessArgs Condition="'$(WasmXHarnessTestsTimeout)' != ''" >$(_XHarnessArgs) &quot;--timeout=$(WasmXHarnessTestsTimeout)&quot;</_XHarnessArgs>
     <_XHarnessArgs Condition="'$(WasmXHarnessArgsCli)' != ''"      >$(_XHarnessArgs) $(WasmXHarnessArgsCli)</_XHarnessArgs>
     
     <_InvariantGlobalization Condition="'$(InvariantGlobalization)' == 'true'">--env=DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=true</_InvariantGlobalization>
diff --git a/eng/testing/tests.wasm.targets b/eng/testing/tests.wasm.targets
index dab07a052796a0..9c019508e47324 100644
--- a/eng/testing/tests.wasm.targets
+++ b/eng/testing/tests.wasm.targets
@@ -16,7 +16,7 @@
     <_ShellCommandSeparator Condition="'$(OS)' == 'Windows_NT'">&amp;&amp;</_ShellCommandSeparator>
     <_ShellCommandSeparator Condition="'$(OS)' != 'Windows_NT'">&amp;&amp;</_ShellCommandSeparator>
     <XUnitUseRandomizedTestOrderer Condition="'$(XUnitUseRandomizedTestOrderer)' == '' and '$(IsTestProject)' == 'true'">true</XUnitUseRandomizedTestOrderer>
-    <_XHarnessTestsTimeout>00:30:00</_XHarnessTestsTimeout>
+    <WasmXHarnessTestsTimeout Condition="'$(WasmXHarnessTestsTimeout)' == ''">00:30:00</WasmXHarnessTestsTimeout>
     <RunWorkingDirectory>$(BundleDir)</RunWorkingDirectory>
   </PropertyGroup>
 
diff --git a/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/System.Text.Json.Tests.csproj b/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/System.Text.Json.Tests.csproj
index 565f6a8ab3daf2..ac3753c325db00 100644
--- a/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/System.Text.Json.Tests.csproj
+++ b/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/System.Text.Json.Tests.csproj
@@ -15,7 +15,7 @@
     <DebuggerSupport Condition="'$(DebuggerSupport)' == '' and '$(TargetOS)' == 'browser'">true</DebuggerSupport>
     <!-- Needed for JsonSerializerOptionsUpdateHandler tests -->
     <MetadataUpdaterSupport Condition="'$(MetadataUpdaterSupport)' == '' and '$(TargetOS)' == 'browser'">true</MetadataUpdaterSupport>
-    <WasmXHarnessArgs>$(WasmXHarnessArgs) --timeout=1800</WasmXHarnessArgs>
+    <WasmXHarnessTestsTimeout>00:45:00</WasmXHarnessTestsTimeout>
     <IncludeRemoteExecutor>true</IncludeRemoteExecutor>
   </PropertyGroup>
   <ItemGroup Condition="'$(ContinuousIntegrationBuild)' == 'true'">