diff --git a/qtcreator.pri b/qtcreator.pri
index e4b262fd16b882b43dc7169deb5cfaddb6e370a2..6668a78080ba63e105b2cf7eb1e4ab7aba2ff49a 100644
--- a/qtcreator.pri
+++ b/qtcreator.pri
@@ -75,8 +75,11 @@ isEmpty(TEST):CONFIG(debug, debug|release) {
 isEmpty(IDE_LIBRARY_BASENAME) {
     IDE_LIBRARY_BASENAME = lib
 }
-
-DEFINES += IDE_LIBRARY_BASENAME=\\\"$$IDE_LIBRARY_BASENAME\\\"
+win32-msvc* {
+    DEFINES += IDE_LIBRARY_BASENAME=\"$$IDE_LIBRARY_BASENAME\"
+} else {
+    DEFINES += IDE_LIBRARY_BASENAME=\\\"$$IDE_LIBRARY_BASENAME\\\"
+}
 
 equals(TEST, 1) {
     QT +=testlib
diff --git a/src/libs/extensionsystem/extensionsystem.pro b/src/libs/extensionsystem/extensionsystem.pro
index 3d9b36c44c3ebec45ebae2304540de3e56908731..42b5ef414050e941cfc2f0df1f6c3afe7086dc1d 100644
--- a/src/libs/extensionsystem/extensionsystem.pro
+++ b/src/libs/extensionsystem/extensionsystem.pro
@@ -6,7 +6,11 @@ include(extensionsystem_dependencies.pri)
 
 unix:!macx:!freebsd*:LIBS += -ldl
 
-DEFINES += IDE_TEST_DIR=\\\"$$IDE_SOURCE_TREE\\\"
+win32-msvc* {
+    DEFINES += IDE_TEST_DIR=\"$$IDE_SOURCE_TREE\"
+} else {
+    DEFINES += IDE_TEST_DIR=\\\"$$IDE_SOURCE_TREE\\\"
+}
 
 HEADERS += pluginerrorview.h \
     plugindetailsview.h \