diff --git a/src/tools/clangbackend/ipcsource/translationunits.cpp b/src/tools/clangbackend/ipcsource/translationunits.cpp
index 5ec8be8810c..713c4e59755 100644
--- a/src/tools/clangbackend/ipcsource/translationunits.cpp
+++ b/src/tools/clangbackend/ipcsource/translationunits.cpp
@@ -282,9 +282,10 @@ TranslationUnit TranslationUnits::createTranslationUnit(const FileContainer &fil
 
 void TranslationUnits::updateTranslationUnit(const FileContainer &fileContainer)
 {
-    auto findIterator = findAllTranslationUnitWithFilePath(fileContainer.filePath());
-    if (findIterator != translationUnits_.end())
-        findIterator->setDocumentRevision(fileContainer.documentRevision());
+    const auto translationUnits = findAllTranslationUnitWithFilePath(fileContainer.filePath());
+
+    for (auto translationUnit : translationUnits)
+        translationUnit.setDocumentRevision(fileContainer.documentRevision());
 }
 
 std::vector<TranslationUnit>::iterator TranslationUnits::findTranslationUnit(const FileContainer &fileContainer)
@@ -292,13 +293,19 @@ std::vector<TranslationUnit>::iterator TranslationUnits::findTranslationUnit(con
     return std::find(translationUnits_.begin(), translationUnits_.end(), fileContainer);
 }
 
-std::vector<TranslationUnit>::iterator TranslationUnits::findAllTranslationUnitWithFilePath(const Utf8String &filePath)
+std::vector<TranslationUnit> TranslationUnits::findAllTranslationUnitWithFilePath(const Utf8String &filePath)
 {
-    auto filePathCompare = [&filePath] (const TranslationUnit &translationUnit) {
+    const auto filePathCompare = [&filePath] (const TranslationUnit &translationUnit) {
         return translationUnit.filePath() == filePath;
     };
 
-    return std::find_if(translationUnits_.begin(), translationUnits_.end(), filePathCompare);
+    std::vector<TranslationUnit> translationUnits;
+    std::copy_if(translationUnits_.begin(),
+                 translationUnits_.end(),
+                 std::back_inserter(translationUnits),
+                 filePathCompare);
+
+    return translationUnits;
 }
 
 std::vector<TranslationUnit>::const_iterator TranslationUnits::findTranslationUnit(const Utf8String &filePath, const Utf8String &projectPartId) const
diff --git a/src/tools/clangbackend/ipcsource/translationunits.h b/src/tools/clangbackend/ipcsource/translationunits.h
index d30ca982504..e8fea785bd8 100644
--- a/src/tools/clangbackend/ipcsource/translationunits.h
+++ b/src/tools/clangbackend/ipcsource/translationunits.h
@@ -94,7 +94,7 @@ private:
     TranslationUnit createTranslationUnit(const FileContainer &fileContainer);
     void updateTranslationUnit(const FileContainer &fileContainer);
     std::vector<TranslationUnit>::iterator findTranslationUnit(const FileContainer &fileContainer);
-    std::vector<TranslationUnit>::iterator findAllTranslationUnitWithFilePath(const Utf8String &filePath);
+    std::vector<TranslationUnit> findAllTranslationUnitWithFilePath(const Utf8String &filePath);
     std::vector<TranslationUnit>::const_iterator findTranslationUnit(const Utf8String &filePath, const Utf8String &projectPartId) const;
     bool hasTranslationUnit(const FileContainer &fileContainer) const;
     bool hasTranslationUnitWithFilePath(const Utf8String &filePath) const;
diff --git a/tests/unit/unittest/translationunitstest.cpp b/tests/unit/unittest/translationunitstest.cpp
index 94599b0a222..220cb81a178 100644
--- a/tests/unit/unittest/translationunitstest.cpp
+++ b/tests/unit/unittest/translationunitstest.cpp
@@ -99,6 +99,7 @@ protected:
     const Utf8String headerPath = Utf8StringLiteral(TESTDATA_DIR"/translationunits.h");
     const Utf8String nonExistingFilePath = Utf8StringLiteral("foo.cpp");
     const Utf8String projectPartId = Utf8StringLiteral("projectPartId");
+    const Utf8String otherProjectPartId = Utf8StringLiteral("otherProjectPartId");
     const Utf8String nonExistingProjectPartId = Utf8StringLiteral("nonExistingProjectPartId");
     const ClangBackEnd::FileContainer fileContainer{filePath, projectPartId};
     const ClangBackEnd::FileContainer headerContainer{headerPath, projectPartId};
@@ -178,7 +179,7 @@ TEST_F(TranslationUnits, ThrowForUpdatingANonExistingTranslationUnit)
                  ClangBackEnd::TranslationUnitDoesNotExistException);
 }
 
-TEST_F(TranslationUnits, Update)
+TEST_F(TranslationUnits, UpdateSingle)
 {
     ClangBackEnd::FileContainer createFileContainer(filePath, projectPartId, Utf8StringVector(), 74u);
     ClangBackEnd::FileContainer updateFileContainer(filePath, Utf8String(), Utf8StringVector(), 75u);
@@ -190,6 +191,21 @@ TEST_F(TranslationUnits, Update)
                 IsTranslationUnit(filePath, projectPartId, 75u));
 }
 
+TEST_F(TranslationUnits, UpdateMultiple)
+{
+    ClangBackEnd::FileContainer fileContainer(filePath, projectPartId, Utf8StringVector(), 74u);
+    ClangBackEnd::FileContainer fileContainerWithOtherProject(filePath, otherProjectPartId, Utf8StringVector(), 74u);
+    ClangBackEnd::FileContainer updatedFileContainer(filePath, Utf8String(), Utf8StringVector(), 75u);
+    translationUnits.create({fileContainer, fileContainerWithOtherProject});
+
+    translationUnits.update({updatedFileContainer});
+
+    ASSERT_THAT(translationUnits.translationUnit(filePath, projectPartId),
+                IsTranslationUnit(filePath, projectPartId, 75u));
+    ASSERT_THAT(translationUnits.translationUnit(filePath, otherProjectPartId),
+                IsTranslationUnit(filePath, otherProjectPartId, 75u));
+}
+
 TEST_F(TranslationUnits, UpdateUnsavedFileAndCheckForReparse)
 {
     ClangBackEnd::FileContainer fileContainer(filePath, projectPartId, Utf8StringVector(), 74u);
@@ -509,6 +525,7 @@ TEST_F(TranslationUnits, SendDocumentAnnotationsAfterProjectPartChange)
 void TranslationUnits::SetUp()
 {
     projects.createOrUpdate({ProjectPartContainer(projectPartId)});
+    projects.createOrUpdate({ProjectPartContainer(otherProjectPartId)});
 
     auto callback = [&] (const DiagnosticsChangedMessage &, const HighlightingChangedMessage &) {
         mockSendDocumentAnnotationsCallback.sendDocumentAnnotations();