diff --git a/Source/cmake.cxx b/Source/cmake.cxx
index c1c26989d..9c4f7d913 100644
--- a/Source/cmake.cxx
+++ b/Source/cmake.cxx
@@ -217,7 +217,8 @@ bool cmake::SetCacheArgs(const std::vector<std::string>& args)
       }
     else if(arg.find("-P",0) == 0)
       {
-      std::string path = arg.substr(strlen("-P"));
+      i++;
+      std::string path = args[i];
       if ( path.size() == 0 )
         {
         cmSystemTools::Error("No cmake scrpt provided.");
diff --git a/Source/cmakemain.cxx b/Source/cmakemain.cxx
index 7c9a15524..3b29bf541 100644
--- a/Source/cmakemain.cxx
+++ b/Source/cmakemain.cxx
@@ -185,8 +185,14 @@ int do_cmake(int ac, char** av)
       }
     else if (strncmp(av[i], "-P", strlen("-P")) == 0)
       {
+      if ( i == ac -1 )
+        {
+        cmSystemTools::Error("No script specified for argument -P");
+        }
       script_mode = true;
       args.push_back(av[i]);
+      i++;
+      args.push_back(av[i]);
       }
     else 
       {
diff --git a/Tests/SimpleInstall/CMakeLists.txt b/Tests/SimpleInstall/CMakeLists.txt
index 4a315a185..ed46a0f64 100644
--- a/Tests/SimpleInstall/CMakeLists.txt
+++ b/Tests/SimpleInstall/CMakeLists.txt
@@ -71,7 +71,7 @@ ADD_CUSTOM_COMMAND(
   POST_BUILD
   COMMAND ${CMAKE_COMMAND}
   ARGS ${EXTRA_INSTALL_FLAGS} 
-  "-P${CMAKE_CURRENT_BINARY_DIR}/cmake_install.cmake"
+  -P "${CMAKE_CURRENT_BINARY_DIR}/cmake_install.cmake"
   COMMENT "Install Project"
   )
 
diff --git a/Tests/SimpleInstallS2/CMakeLists.txt b/Tests/SimpleInstallS2/CMakeLists.txt
index 4a315a185..ed46a0f64 100644
--- a/Tests/SimpleInstallS2/CMakeLists.txt
+++ b/Tests/SimpleInstallS2/CMakeLists.txt
@@ -71,7 +71,7 @@ ADD_CUSTOM_COMMAND(
   POST_BUILD
   COMMAND ${CMAKE_COMMAND}
   ARGS ${EXTRA_INSTALL_FLAGS} 
-  "-P${CMAKE_CURRENT_BINARY_DIR}/cmake_install.cmake"
+  -P "${CMAKE_CURRENT_BINARY_DIR}/cmake_install.cmake"
   COMMENT "Install Project"
   )