diff --git a/Source/cmGlobalNinjaGenerator.cxx b/Source/cmGlobalNinjaGenerator.cxx
index 7d62fa8f5b..b051d67a65 100644
--- a/Source/cmGlobalNinjaGenerator.cxx
+++ b/Source/cmGlobalNinjaGenerator.cxx
@@ -573,13 +573,7 @@ cmGlobalNinjaGenerator::cmGlobalNinjaGenerator(cmake* cm)
   cm->GetState()->SetWindowsShell(true);
 
   // Attempt to use full path to COMSPEC, default "cmd.exe"
-  std::string comspec;
-  if (cmSystemTools::GetEnv("COMSPEC", comspec) &&
-      cmSystemTools::FileIsFullPath(comspec)) {
-    this->Comspec = comspec;
-  } else {
-    this->Comspec = "cmd.exe";
-  }
+  this->Comspec = cmSystemTools::GetComspec();
 #endif
   cm->GetState()->SetNinja(true);
   this->FindMakeProgramFile = "CMakeNinjaFindMake.cmake";
diff --git a/Source/cmSystemTools.cxx b/Source/cmSystemTools.cxx
index 8e59a358ec..05cc85a332 100644
--- a/Source/cmSystemTools.cxx
+++ b/Source/cmSystemTools.cxx
@@ -970,6 +970,17 @@ cmSystemTools::WindowsVersion cmSystemTools::GetWindowsVersion()
   result.dwBuildNumber = osviex.dwBuildNumber;
   return result;
 }
+
+std::string cmSystemTools::GetComspec()
+{
+  std::string comspec;
+  if (!cmSystemTools::GetEnv("COMSPEC", comspec) ||
+      !cmSystemTools::FileIsFullPath(comspec)) {
+    comspec = "cmd.exe";
+  }
+  return comspec;
+}
+
 #endif
 
 std::string cmSystemTools::GetRealPathResolvingWindowsSubst(
diff --git a/Source/cmSystemTools.h b/Source/cmSystemTools.h
index a07c749985..d0b604610c 100644
--- a/Source/cmSystemTools.h
+++ b/Source/cmSystemTools.h
@@ -585,6 +585,9 @@ public:
     unsigned int dwBuildNumber;
   };
   static WindowsVersion GetWindowsVersion();
+
+  /** Attempt to get full path to COMSPEC, default "cmd.exe" */
+  static std::string GetComspec();
 #endif
 
   /** Get the real path for a given path, removing all symlinks.