diff --git a/README.md b/README.md
index 13f9dbda8ee..af745d7326e 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@ The standalone binary packages support the following platforms:
 
 Prerequisites:
 
-* Qt 5.6.2 or later
+* Qt 5.9.0 or later
 * Qt WebEngine module for QtWebEngine based help viewer
 * On Windows:
     * ActiveState Active Perl
@@ -66,7 +66,7 @@ For detailed information on the supported compilers, see
        for example, `c:\work`. If you plan to use MinGW and Microsoft Visual
        Studio simultaneously or mix different Qt versions, we recommend
        creating a directory structure which reflects that. For example:
-       `C:\work\qt5.6.0-vs12, C:\work\qt5.6.0-mingw`.
+       `C:\work\qt5.9.0-vs12, C:\work\qt5.9.0-mingw`.
 
    4.  Download and install Perl from <https://www.activestate.com/activeperl>
        and check that perl.exe is added to the path. Run `perl -v` to verify
@@ -476,4 +476,3 @@ SQLite (https://www.sqlite.org) is in the Public Domain.
   This Font Software is licensed under the SIL Open Font License, Version 1.1.
 
   The font and license files can be found in QtCreator/src/libs/3rdparty/fonts.
-
diff --git a/qbs/imports/QtcProduct.qbs b/qbs/imports/QtcProduct.qbs
index fc6c2502e40..0dc1e9b3b1f 100644
--- a/qbs/imports/QtcProduct.qbs
+++ b/qbs/imports/QtcProduct.qbs
@@ -20,7 +20,7 @@ Product {
     Depends { name: "cpp" }
     Depends { name: "qtc" }
     Depends { name: product.name + " dev headers"; required: false }
-    Depends { name: "Qt.core"; versionAtLeast: "5.6.2" }
+    Depends { name: "Qt.core"; versionAtLeast: "5.9.0" }
 
     // TODO: Should fall back to what came from Qt.core for Qt < 5.7, but we cannot express that
     //       atm. Conditionally pulling in a module that sets the property is also not possible,
diff --git a/qtcreator.pro b/qtcreator.pro
index f52b6c242c8..c4324555ba8 100644
--- a/qtcreator.pro
+++ b/qtcreator.pro
@@ -1,9 +1,9 @@
 include(qtcreator.pri)
 
 #version check qt
-!minQtVersion(5, 6, 2) {
+!minQtVersion(5, 9, 0) {
     message("Cannot build $$IDE_DISPLAY_NAME with Qt version $${QT_VERSION}.")
-    error("Use at least Qt 5.6.2.")
+    error("Use at least Qt 5.9.0.")
 }
 
 include(doc/doc.pri)