diff --git a/cpp/ycm/ClangCompleter/ClangCompleter.cpp b/cpp/ycm/ClangCompleter/ClangCompleter.cpp
index b50801c6..d1fda853 100644
--- a/cpp/ycm/ClangCompleter/ClangCompleter.cpp
+++ b/cpp/ycm/ClangCompleter/ClangCompleter.cpp
@@ -101,8 +101,10 @@ ClangCompleter::~ClangCompleter() {
   sorting_threads_.interrupt_all();
   sorting_threads_.join_all();
 
-  clang_thread_->interrupt();
-  clang_thread_->join();
+  if ( clang_thread_ ) {
+    clang_thread_->interrupt();
+    clang_thread_->join();
+  }
 }
 
 
diff --git a/cpp/ycm/IdentifierCompleter.cpp b/cpp/ycm/IdentifierCompleter.cpp
index ec7c62e3..8f3b2c21 100644
--- a/cpp/ycm/IdentifierCompleter.cpp
+++ b/cpp/ycm/IdentifierCompleter.cpp
@@ -103,8 +103,10 @@ IdentifierCompleter::~IdentifierCompleter() {
   query_threads_.interrupt_all();
   query_threads_.join_all();
 
-  buffer_identifiers_thread_->interrupt();
-  buffer_identifiers_thread_->join();
+  if ( buffer_identifiers_thread_ ) {
+    buffer_identifiers_thread_->interrupt();
+    buffer_identifiers_thread_->join();
+  }
 }