diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index 7ca7684c4..b64383fb1 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -2270,7 +2270,14 @@ AddCompilerRequirementFlag(std::string &flags, cmTarget* target,
 
   std::vector<std::string>::const_iterator stdIt =
                                 std::find(stds.begin(), stds.end(), standard);
-  assert(stdIt != stds.end());
+  if (stdIt == stds.end())
+    {
+    std::string e =
+      lang + "_STANDARD is set to invalid value '" + standard + "'";
+    this->GetGlobalGenerator()->GetCMakeInstance()
+      ->IssueMessage(cmake::FATAL_ERROR, e, target->GetBacktrace());
+    return;
+    }
 
   std::vector<std::string>::const_iterator defaultStdIt =
     std::find(stds.begin(), stds.end(), defaultStd);
diff --git a/Tests/RunCMake/CompileFeatures/NotAStandard-result.txt b/Tests/RunCMake/CompileFeatures/NotAStandard-result.txt
new file mode 100644
index 000000000..d00491fd7
--- /dev/null
+++ b/Tests/RunCMake/CompileFeatures/NotAStandard-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/CompileFeatures/NotAStandard-stderr.txt b/Tests/RunCMake/CompileFeatures/NotAStandard-stderr.txt
new file mode 100644
index 000000000..deab12f82
--- /dev/null
+++ b/Tests/RunCMake/CompileFeatures/NotAStandard-stderr.txt
@@ -0,0 +1,4 @@
+CMake Error at NotAStandard.cmake:[0-9]+ \(add_library\):
+  CXX_STANDARD is set to invalid value 'bad'
+Call Stack \(most recent call first\):
+  CMakeLists.txt:[0-9]+ \(include\)
diff --git a/Tests/RunCMake/CompileFeatures/NotAStandard.cmake b/Tests/RunCMake/CompileFeatures/NotAStandard.cmake
new file mode 100644
index 000000000..11529d85a
--- /dev/null
+++ b/Tests/RunCMake/CompileFeatures/NotAStandard.cmake
@@ -0,0 +1,2 @@
+set(CMAKE_CXX_STANDARD bad)
+add_library(somelib STATIC empty.cpp)
diff --git a/Tests/RunCMake/CompileFeatures/RunCMakeTest.cmake b/Tests/RunCMake/CompileFeatures/RunCMakeTest.cmake
index 833a3150e..c1b2227da 100644
--- a/Tests/RunCMake/CompileFeatures/RunCMakeTest.cmake
+++ b/Tests/RunCMake/CompileFeatures/RunCMakeTest.cmake
@@ -43,6 +43,8 @@ else()
 endif()
 
 if(CXX_STANDARD_DEFAULT)
+  run_cmake(NotAStandard)
+
   foreach(standard 98 11)
     file(READ
       "${RunCMake_BINARY_DIR}/generate_feature_list-build/cxx${standard}_flag.txt"