diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index 119cba9d8..6f98ee2a0 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -1341,7 +1341,7 @@ void cmLocalGenerator::GetIncludeDirectories(std::vector<std::string>& dirs,
                                              const std::string& lang,
                                              const std::string& config,
                                              bool stripImplicitInclDirs
-                                            )
+                                            ) const
 {
   // Need to decide whether to automatically include the source and
   // binary directories at the beginning of the include path.
diff --git a/Source/cmLocalGenerator.h b/Source/cmLocalGenerator.h
index a3f95886e..98f4d3a22 100644
--- a/Source/cmLocalGenerator.h
+++ b/Source/cmLocalGenerator.h
@@ -183,7 +183,7 @@ public:
                              cmGeneratorTarget* target,
                              const std::string& lang = "C",
                              const std::string& config = "",
-                             bool stripImplicitInclDirs = true);
+                             bool stripImplicitInclDirs = true) const;
   void AddCompileOptions(std::string& flags, cmTarget* target,
                          const std::string& lang, const std::string& config);
   void AddCompileDefinitions(std::set<std::string>& defines,