diff --git a/src/libs/utils/codegeneration.cpp b/src/libs/utils/codegeneration.cpp
index c0b1a64356a..f5975fe0fb6 100644
--- a/src/libs/utils/codegeneration.cpp
+++ b/src/libs/utils/codegeneration.cpp
@@ -35,7 +35,7 @@
 
 namespace Utils {
 
-static QString toAlphaNum(const QString &s)
+QTCREATOR_UTILS_EXPORT QString fileNameToCppIdentifier(const QString &s)
 {
     QString rc;
     const int len = s.size();
@@ -55,9 +55,9 @@ static QString toAlphaNum(const QString &s)
 QTCREATOR_UTILS_EXPORT QString headerGuard(const QString &file)
 {
     const QFileInfo fi(file);
-    QString rc = toAlphaNum(fi.completeBaseName()).toUpper();
+    QString rc = fileNameToCppIdentifier(fi.completeBaseName()).toUpper();
     rc += QLatin1Char('_');
-    rc += toAlphaNum(fi.suffix()).toUpper();
+    rc += fileNameToCppIdentifier(fi.suffix()).toUpper();
     return rc;
 }
 
diff --git a/src/libs/utils/codegeneration.h b/src/libs/utils/codegeneration.h
index 5c8fc746ce7..6f0ec6c7e1d 100644
--- a/src/libs/utils/codegeneration.h
+++ b/src/libs/utils/codegeneration.h
@@ -40,6 +40,10 @@ QT_END_NAMESPACE
 
 namespace Utils {
 
+// Convert a file name to a Cpp identifier (stripping invalid characters
+// or replacing them by an underscore).
+QTCREATOR_UTILS_EXPORT QString fileNameToCppIdentifier(const QString &s);
+
 QTCREATOR_UTILS_EXPORT QString headerGuard(const QString &file);
 
 QTCREATOR_UTILS_EXPORT
diff --git a/src/plugins/qt4projectmanager/wizards/qtprojectparameters.cpp b/src/plugins/qt4projectmanager/wizards/qtprojectparameters.cpp
index 0cfbb7dcaa2..a658a6bc223 100644
--- a/src/plugins/qt4projectmanager/wizards/qtprojectparameters.cpp
+++ b/src/plugins/qt4projectmanager/wizards/qtprojectparameters.cpp
@@ -28,6 +28,7 @@
 **************************************************************************/
 
 #include "qtprojectparameters.h"
+#include <utils/codegeneration.h>
 
 #include <QtCore/QTextStream>
 #include <QtCore/QDir>
@@ -108,7 +109,7 @@ QString createMacro(const QString &name, const QString &suffix)
     if (extensionPosition != -1)
         rc.truncate(extensionPosition);
     rc += suffix;
-    return rc;
+    return Utils::fileNameToCppIdentifier(rc);
 }
 
 QString QtProjectParameters::exportMacro(const QString &projectName)