diff --git a/Modules/CMakeDetermineCompilerId.cmake b/Modules/CMakeDetermineCompilerId.cmake
index 908e530..7b571c3 100644
--- a/Modules/CMakeDetermineCompilerId.cmake
+++ b/Modules/CMakeDetermineCompilerId.cmake
@@ -284,10 +284,11 @@
           set(id_cl icl.exe)
         endif()
         if(CMAKE_VS_PLATFORM_TOOLSET_VERSION)
+          set(id_sep "\\")
           if(CMAKE_VS_PLATFORM_TOOLSET_VERSION VERSION_GREATER_EQUAL "14.20")
-            set(id_sep ".")
-          else()
-            set(id_sep "\\")
+            if(EXISTS "${CMAKE_GENERATOR_INSTANCE}/VC/Auxiliary/Build.${CMAKE_VS_PLATFORM_TOOLSET_VERSION}/Microsoft.VCToolsVersion.${CMAKE_VS_PLATFORM_TOOLSET_VERSION}.props")
+              set(id_sep ".")
+            endif()
           endif()
           set(id_toolset_version_props "<Import Project=\"${CMAKE_GENERATOR_INSTANCE}\\VC\\Auxiliary\\Build${id_sep}${CMAKE_VS_PLATFORM_TOOLSET_VERSION}\\Microsoft.VCToolsVersion.${CMAKE_VS_PLATFORM_TOOLSET_VERSION}.props\" />")
           unset(id_sep)
diff --git a/Source/cmGlobalVisualStudioVersionedGenerator.cxx b/Source/cmGlobalVisualStudioVersionedGenerator.cxx
index 1eca1f6..a371633 100644
--- a/Source/cmGlobalVisualStudioVersionedGenerator.cxx
+++ b/Source/cmGlobalVisualStudioVersionedGenerator.cxx
@@ -6,6 +6,7 @@
 #include "cmDocumentationEntry.h"
 #include "cmLocalVisualStudio10Generator.h"
 #include "cmMakefile.h"
+#include "cmStringAlgorithms.h"
 #include "cmVSSetupHelper.h"
 #include "cmake.h"
 
@@ -388,15 +389,19 @@
   if (version) {
     std::string instancePath;
     GetVSInstance(instancePath);
-    std::stringstream path;
-    path << instancePath;
-    path << "/VC/Auxiliary/Build";
-    path << (cmSystemTools::VersionCompareGreaterEq(version, "14.20") ? '.'
-                                                                      : '/');
-    path << version;
-    path << "/Microsoft.VCToolsVersion." << version << ".props";
-
-    std::string toolsetPath = path.str();
+    std::string toolsetDir = instancePath + "/VC/Auxiliary/Build";
+    char sep = '/';
+    if (cmSystemTools::VersionCompareGreaterEq(version, "14.20")) {
+      std::string toolsetDot =
+        cmStrCat(toolsetDir, '.', version, "/Microsoft.VCToolsVersion.",
+                 version, ".props");
+      if (cmSystemTools::PathExists(toolsetDot)) {
+        sep = '.';
+      }
+    }
+    std::string toolsetPath =
+      cmStrCat(toolsetDir, sep, version, "/Microsoft.VCToolsVersion.", version,
+               ".props");
     cmSystemTools::ConvertToUnixSlashes(toolsetPath);
     return toolsetPath;
   }