diff --git a/Source/cmake.cxx b/Source/cmake.cxx
index 973fc2088..aae773ff4 100644
--- a/Source/cmake.cxx
+++ b/Source/cmake.cxx
@@ -299,7 +299,7 @@ bool cmake::SetCacheArgs(const std::vector<std::string>& args)
         {
         this->CacheManager->AddCacheEntry(var.c_str(), value.c_str(),
           "No help, variable specified on the command line.",
-          type);
+          type==cmCacheManager::UNINITIALIZED?cmCacheManager::STRING:type);
         }
       else
         {
@@ -309,6 +309,49 @@ bool cmake::SetCacheArgs(const std::vector<std::string>& args)
         return false;
         }
       }
+    else if(arg.find("-U",0) == 0)
+      {
+      std::string entryPattern = arg.substr(2);
+      if(entryPattern.size() == 0)
+        {
+        ++i;
+        if(i < args.size())
+          {
+          entryPattern = args[i];
+          }
+        else
+          {
+          cmSystemTools::Error("-U must be followed with VAR.");
+          return false;
+          }
+        }
+
+      //go through all cache entries and collect the vars which will be removed
+      std::vector<std::string> entriesToDelete;
+      cmCacheManager::CacheIterator it = 
+                                    this->CacheManager->GetCacheIterator();
+      for ( it.Begin(); !it.IsAtEnd(); it.Next() )
+        {
+        cmCacheManager::CacheEntryType t = it.GetType();
+        if(t != cmCacheManager::STATIC &&  t != cmCacheManager::UNINITIALIZED)
+          {
+          std::string entryName = it.GetName();
+          if (entryName.find(entryPattern) != std::string::npos)
+            {
+            entriesToDelete.push_back(entryName);
+            }
+          }
+        }
+
+      // now remove them from the cache
+      for(std::vector<std::string>::const_iterator currentEntry = 
+          entriesToDelete.begin(); 
+          currentEntry != entriesToDelete.end();
+          ++currentEntry)
+        {
+        this->CacheManager->RemoveCacheEntry(currentEntry->c_str());
+        }
+      }
     else if(arg.find("-C",0) == 0)
       {
       std::string path = arg.substr(2);
@@ -432,6 +475,10 @@ void cmake::SetArgs(const std::vector<std::string>& args)
       {
       // skip for now
       }
+    else if(arg.find("-U",0) == 0)
+      {
+      // skip for now
+      }
     else if(arg.find("-C",0) == 0)
       {
       // skip for now
diff --git a/Source/cmake.h b/Source/cmake.h
index d0ba30074..c1485155f 100644
--- a/Source/cmake.h
+++ b/Source/cmake.h
@@ -388,6 +388,11 @@ private:
    "for the project.  This option may be used to specify a setting " \
    "that takes priority over the project's default value.  The option " \
    "may be repeated for as many cache entries as desired."}, \
+  {"-U <var>", "Remove one or more cmake cache entries.", \
+   "This option may be used to remove one or more variables from the " \
+   "CMakeCache.txt file, so that CMake will search them again. All " \
+   "variables which contain \"<var>\" will be removed. The option may be "\
+   "repeated for as many cache entries as desired."}, \
   {"-G <generator-name>", "Specify a makefile generator.", \
    "CMake may support multiple native build systems on certain platforms.  " \
    "A makefile generator is responsible for generating a particular build " \