diff --git a/src/libs/utils/stringutils.cpp b/src/libs/utils/stringutils.cpp
index 9861aa348e4..5024bd5ab57 100644
--- a/src/libs/utils/stringutils.cpp
+++ b/src/libs/utils/stringutils.cpp
@@ -126,6 +126,11 @@ int AbstractMacroExpander::findMacro(const QString &str, int *pos, QString *ret)
         if (closePos < 0)
             return 0;
         int varLen = closePos - varPos;
+        if (varLen == 0) { // replace "%{}" with "%"
+            *pos = openPos;
+            *ret = QString(QLatin1Char('%'));
+            return 3;
+        }
         if (resolveMacro(str.mid(varPos, varLen), ret)) {
             *pos = openPos;
             return varLen + 3;
diff --git a/tests/auto/utils_stringutils/tst_stringutils.cpp b/tests/auto/utils_stringutils/tst_stringutils.cpp
index 82a0fd7a999..289432cd287 100644
--- a/tests/auto/utils_stringutils/tst_stringutils.cpp
+++ b/tests/auto/utils_stringutils/tst_stringutils.cpp
@@ -42,6 +42,10 @@ public:
             *ret = QLatin1String("hi");
             return true;
         }
+        if (name == QLatin1String("foo")) {
+            *ret = QLatin1String("a");
+            return true;
+        }
         return false;
     }
 };
@@ -102,11 +106,17 @@ void tst_StringUtils::testMacroExpander_data()
     } vals[] = {
         { "text", "text" },
         { "%{a}", "hi" },
+        { "%%{a}", "%hi" },
+        { "%%%{a}", "%%hi" },
+        { "%{b}", "%{b}" },
         { "pre%{a}", "prehi" },
         { "%{a}post", "hipost" },
         { "pre%{a}post", "prehipost" },
         { "%{a}%{a}", "hihi" },
         { "%{a}text%{a}", "hitexthi" },
+        { "%{foo}%{a}text%{a}", "ahitexthi" },
+        { "%{}{a}", "%{a}" },
+        { "%{abc", "%{abc" }
     };
 
     for (unsigned i = 0; i < sizeof(vals)/sizeof(vals[0]); i++)