diff --git a/cli/cli.pro b/cli/cli.pro
index 0d285d9eb..b71023069 100644
--- a/cli/cli.pro
+++ b/cli/cli.pro
@@ -29,6 +29,11 @@ win32 {
 # These flags are used in original (not generated by QMake) makefiles
 contains(QMAKE_CXX, g++) {
     QMAKE_CXXFLAGS_WARN_ON += -Wextra -pedantic
+
+    CONFIG(debug, debug|release) {
+        # checked STL
+        DEFINES += _GLIBCXX_DEBUG
+    }
 }
 
 # Change Visual Studio compiler (CL) warning level to W4
diff --git a/test/test.pro b/test/test.pro
index 8cc687606..c4fe4e592 100644
--- a/test/test.pro
+++ b/test/test.pro
@@ -39,3 +39,14 @@ win32 {
     CONFIG += console
     LIBS += -lshlwapi
 }
+
+contains(QMAKE_CXX, g++) {
+    QMAKE_CXXFLAGS_WARN_ON += -Wextra -pedantic
+
+    CONFIG(debug, debug|release) {
+        # checked STL
+        DEFINES += _GLIBCXX_DEBUG
+    }
+}
+
+