diff --git a/cfg/qt.cfg b/cfg/qt.cfg
index 8d599ed5d3d..a619579545f 100644
--- a/cfg/qt.cfg
+++ b/cfg/qt.cfg
@@ -63,6 +63,7 @@
   <define name="SLOT(X)" value="#X"/>
   <!-- T qAbs(const T &t) -->
   <function name="qAbs">
+    <pure/>
     <noreturn>false</noreturn>
     <use-retval/>
     <arg nr="1" direction="in">
@@ -147,6 +148,7 @@
   <!-- bool qFuzzyIsNull(double d) -->
   <!-- bool qFuzzyIsNull(float f) -->
   <function name="qFuzzyIsNull">
+    <pure/>
     <noreturn>false</noreturn>
     <returnValue type="bool"/>
     <use-retval/>
@@ -2338,6 +2340,8 @@
   <!-- bool QDir::exists(QString &name) const -->
   <!-- bool QDir::exists() const -->
   <function name="QDir">
+    <pure/>
+    <const/>
     <noreturn>false</noreturn>
     <returnValue type="bool"/>
     <use-retval/>
@@ -2722,6 +2726,7 @@
   <!-- bool QDate::isValid() const -->
   <!-- bool QDate::isValid(int year, int month, int day) // static -->
   <function name="QDate::isValid">
+    <pure/>
     <noreturn>false</noreturn>
     <returnValue type="bool"/>
     <use-retval/>