diff --git a/icu4c/source/layoutex/layoutex.vcxproj b/icu4c/source/layoutex/layoutex.vcxproj
index 3da6579f2a5..9e594c8f1ab 100644
--- a/icu4c/source/layoutex/layoutex.vcxproj
+++ b/icu4c/source/layoutex/layoutex.vcxproj
@@ -92,7 +92,7 @@
       <StringPooling>true</StringPooling>
       <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
       <FunctionLevelLinking>true</FunctionLevelLinking>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
       <TreatWChar_tAsBuiltInType>true</TreatWChar_tAsBuiltInType>
       <PrecompiledHeaderOutputFile>.\x86\Release/layoutex.pch</PrecompiledHeaderOutputFile>
       <AssemblerListingLocation>.\x86\Release/</AssemblerListingLocation>
@@ -133,7 +133,7 @@
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
       <BufferSecurityCheck>true</BufferSecurityCheck>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
       <TreatWChar_tAsBuiltInType>true</TreatWChar_tAsBuiltInType>
       <PrecompiledHeaderOutputFile>.\x86\Debug/layoutex.pch</PrecompiledHeaderOutputFile>
       <AssemblerListingLocation>.\x86\Debug/</AssemblerListingLocation>
@@ -175,7 +175,7 @@
       <StringPooling>true</StringPooling>
       <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
       <FunctionLevelLinking>true</FunctionLevelLinking>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
       <TreatWChar_tAsBuiltInType>true</TreatWChar_tAsBuiltInType>
       <PrecompiledHeaderOutputFile>.\x64\Release/layoutex.pch</PrecompiledHeaderOutputFile>
       <AssemblerListingLocation>.\x64\Release/</AssemblerListingLocation>
@@ -214,7 +214,7 @@
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
       <BufferSecurityCheck>true</BufferSecurityCheck>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
       <TreatWChar_tAsBuiltInType>true</TreatWChar_tAsBuiltInType>
       <PrecompiledHeaderOutputFile>.\x64\Debug/layoutex.pch</PrecompiledHeaderOutputFile>
       <AssemblerListingLocation>.\x64\Debug/</AssemblerListingLocation>
diff --git a/icu4c/source/tools/toolutil/toolutil.vcxproj b/icu4c/source/tools/toolutil/toolutil.vcxproj
index fd6c26508c3..1f7b03a5531 100644
--- a/icu4c/source/tools/toolutil/toolutil.vcxproj
+++ b/icu4c/source/tools/toolutil/toolutil.vcxproj
@@ -92,7 +92,7 @@
       <StringPooling>true</StringPooling>
       <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
       <FunctionLevelLinking>true</FunctionLevelLinking>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
       <TreatWChar_tAsBuiltInType>true</TreatWChar_tAsBuiltInType>
       <PrecompiledHeaderOutputFile>.\x86\Release/toolutil.pch</PrecompiledHeaderOutputFile>
       <AssemblerListingLocation>.\x86\Release/</AssemblerListingLocation>
@@ -135,7 +135,7 @@
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
       <BufferSecurityCheck>true</BufferSecurityCheck>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
       <TreatWChar_tAsBuiltInType>true</TreatWChar_tAsBuiltInType>
       <PrecompiledHeaderOutputFile>.\x86\Debug/toolutil.pch</PrecompiledHeaderOutputFile>
       <AssemblerListingLocation>.\x86\Debug/</AssemblerListingLocation>
@@ -178,7 +178,7 @@
       <StringPooling>true</StringPooling>
       <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
       <FunctionLevelLinking>true</FunctionLevelLinking>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
       <TreatWChar_tAsBuiltInType>true</TreatWChar_tAsBuiltInType>
       <PrecompiledHeaderOutputFile>.\x64\Release/toolutil.pch</PrecompiledHeaderOutputFile>
       <AssemblerListingLocation>.\x64\Release/</AssemblerListingLocation>
@@ -219,7 +219,7 @@
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
       <BufferSecurityCheck>true</BufferSecurityCheck>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
       <TreatWChar_tAsBuiltInType>true</TreatWChar_tAsBuiltInType>
       <PrecompiledHeaderOutputFile>.\x64\Debug/toolutil.pch</PrecompiledHeaderOutputFile>
       <AssemblerListingLocation>.\x64\Debug/</AssemblerListingLocation>