diff --git a/src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp b/src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp
index 09f5ee95075..592f7c8795c 100644
--- a/src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp
+++ b/src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp
@@ -215,8 +215,11 @@ void ClangCompletionAssistProcessor::handleAvailableCompletions(const CodeComple
             return;
         }
 
-        if (!m_fallbackToNormalCompletion)
+        if (!m_fallbackToNormalCompletion) {
+            // We must report back to the code assistant under all circumstances
+            setAsyncProposalAvailable(nullptr);
             return;
+        }
         // else: Proceed with a normal completion in case:
         // 1) it was not a function call, but e.g. a function declaration like "void f("
         // 2) '{' meant not a constructor call.
diff --git a/src/plugins/languageclient/languageclientcompletionassist.cpp b/src/plugins/languageclient/languageclientcompletionassist.cpp
index ae2eca2ff63..54b9740809c 100644
--- a/src/plugins/languageclient/languageclientcompletionassist.cpp
+++ b/src/plugins/languageclient/languageclientcompletionassist.cpp
@@ -35,6 +35,7 @@
 #include <texteditor/codeassist/genericproposal.h>
 #include <texteditor/codeassist/genericproposalmodel.h>
 #include <utils/algorithm.h>
+#include <utils/executeondestruction.h>
 #include <utils/textutils.h>
 #include <utils/utilsicons.h>
 
@@ -361,6 +362,9 @@ void LanguageClientCompletionAssistProcessor::cancel()
 void LanguageClientCompletionAssistProcessor::handleCompletionResponse(
     const CompletionRequest::Response &response)
 {
+    LanguageClientCompletionProposal *proposal = nullptr;
+    // We must report back to the code assistant under all circumstances
+    Utils::ExecuteOnDestruction eod([this, proposal]() { setAsyncProposalAvailable(proposal); });
     qCDebug(LOGLSPCOMPLETION) << QTime::currentTime() << " : got completions";
     m_currentRequest = MessageId();
     QTC_ASSERT(m_client, return);
@@ -383,12 +387,11 @@ void LanguageClientCompletionAssistProcessor::handleCompletionResponse(
     model->loadContent(Utils::transform(items, [](const CompletionItem &item){
         return static_cast<AssistProposalItemInterface *>(new LanguageClientCompletionItem(item));
     }));
-    auto proposal = new LanguageClientCompletionProposal(m_pos, model);
+    proposal = new LanguageClientCompletionProposal(m_pos, model);
     proposal->m_document = m_document;
     proposal->m_pos = m_pos;
     proposal->setFragile(true);
     proposal->setSupportsPrefix(false);
-    setAsyncProposalAvailable(proposal);
     qCDebug(LOGLSPCOMPLETION) << QTime::currentTime() << " : "
                               << items.count() << " completions handled";
 }