diff --git a/src/libs/utils/fileutils.cpp b/src/libs/utils/fileutils.cpp
index d5dc5b7a0b5..c3f323aecec 100644
--- a/src/libs/utils/fileutils.cpp
+++ b/src/libs/utils/fileutils.cpp
@@ -236,6 +236,25 @@ QString FileUtils::fileSystemFriendlyName(const QString &name)
     return result;
 }
 
+int FileUtils::indexOfQmakeUnfriendly(const QString &name, int startpos)
+{
+    static QRegExp checkRegExp(QLatin1String("[^a-zA-Z0-9_.-]"));
+    return checkRegExp.indexIn(name, startpos);
+}
+
+QString FileUtils::qmakeFriendlyName(const QString &name)
+{
+    QString result = name;
+
+    // Remove characters that might trip up a build system (especially qmake):
+    int pos = indexOfQmakeUnfriendly(result);
+    while (pos >= 0) {
+        result[pos] = QLatin1Char('_');
+        pos = indexOfQmakeUnfriendly(result, pos);
+    }
+    return fileSystemFriendlyName(result);
+}
+
 bool FileUtils::makeWritable(const FileName &path)
 {
     const QString fileName = path.toString();
diff --git a/src/libs/utils/fileutils.h b/src/libs/utils/fileutils.h
index 96c1d46991d..64ba6581cf8 100644
--- a/src/libs/utils/fileutils.h
+++ b/src/libs/utils/fileutils.h
@@ -97,6 +97,8 @@ public:
     static FileName resolveSymlinks(const FileName &path);
     static QString shortNativePath(const FileName &path);
     static QString fileSystemFriendlyName(const QString &name);
+    static int indexOfQmakeUnfriendly(const QString &name, int startpos = 0);
+    static QString qmakeFriendlyName(const QString &name);
     static bool makeWritable(const FileName &path);
     static QString normalizePathName(const QString &name);
 };
diff --git a/src/libs/utils/projectnamevalidatinglineedit.cpp b/src/libs/utils/projectnamevalidatinglineedit.cpp
index 8a1136a8c12..3d54c4b5744 100644
--- a/src/libs/utils/projectnamevalidatinglineedit.cpp
+++ b/src/libs/utils/projectnamevalidatinglineedit.cpp
@@ -30,6 +30,8 @@
 #include "projectnamevalidatinglineedit.h"
 #include "filenamevalidatinglineedit.h"
 
+#include "fileutils.h"
+
 namespace Utils {
 
 ProjectNameValidatingLineEdit::ProjectNameValidatingLineEdit(QWidget *parent)
@@ -43,8 +45,12 @@ bool ProjectNameValidatingLineEdit::validateProjectName(const QString &name, QSt
     if (!FileNameValidatingLineEdit::validateFileName(name, false, errorMessage))
         return false;
 
-    // We don't want dots in the directory name for some legacy Windows
-    // reason. Since we are cross-platform, we generally disallow it.
+    int pos = FileUtils::indexOfQmakeUnfriendly(name);
+    if (pos >= 0) {
+        if (errorMessage)
+            *errorMessage = tr("Invalid character '%1' found!").arg(name.at(pos));
+        return false;
+    }
     if (name.contains(QLatin1Char('.'))) {
         if (errorMessage)
             *errorMessage = tr("Invalid character '.'.");
diff --git a/src/plugins/projectexplorer/kit.cpp b/src/plugins/projectexplorer/kit.cpp
index 1e25cbdfee1..e9b14673aeb 100644
--- a/src/plugins/projectexplorer/kit.cpp
+++ b/src/plugins/projectexplorer/kit.cpp
@@ -307,14 +307,14 @@ QStringList Kit::candidateNameList(const QString &base) const
 
 QString Kit::fileSystemFriendlyName() const
 {
-    QString name = Utils::FileUtils::fileSystemFriendlyName(displayName());
+    QString name = Utils::FileUtils::qmakeFriendlyName(displayName());
     foreach (Kit *i, KitManager::kits()) {
         if (i == this)
             continue;
-        if (name == Utils::FileUtils::fileSystemFriendlyName(i->displayName())) {
+        if (name == Utils::FileUtils::qmakeFriendlyName(i->displayName())) {
             // append part of the kit id: That should be unique enough;-)
             // Leading { will be turned into _ which should be fine.
-            name = Utils::FileUtils::fileSystemFriendlyName(name + QLatin1Char('_') + (id().toString().left(7)));
+            name = Utils::FileUtils::qmakeFriendlyName(name + QLatin1Char('_') + (id().toString().left(7)));
             break;
         }
     }
diff --git a/src/plugins/qmakeprojectmanager/qmakeprojectconfigwidget.cpp b/src/plugins/qmakeprojectmanager/qmakeprojectconfigwidget.cpp
index 8f28bc8f55b..aaaba787788 100644
--- a/src/plugins/qmakeprojectmanager/qmakeprojectconfigwidget.cpp
+++ b/src/plugins/qmakeprojectmanager/qmakeprojectconfigwidget.cpp
@@ -51,7 +51,7 @@ QmakeProjectConfigWidget::QmakeProjectConfigWidget(QmakeBuildConfiguration *bc)
     m_defaultShadowBuildDir
             = QmakeProject::shadowBuildDirectory(bc->target()->project()->projectFilePath(),
                                                bc->target()->kit(),
-                                               Utils::FileUtils::fileSystemFriendlyName(bc->displayName()));
+                                               Utils::FileUtils::qmakeFriendlyName(bc->displayName()));
 
     QVBoxLayout *vbox = new QVBoxLayout(this);
     vbox->setMargin(0);