diff --git a/src/libs/botan/botan.pro b/src/libs/botan/botan.pro
index eb03ffee855..2f238e5d039 100644
--- a/src/libs/botan/botan.pro
+++ b/src/libs/botan/botan.pro
@@ -28,7 +28,8 @@ mingw {
     OTHER_FLAGS += --without-stack-protector
 }
 BOTAN_CXX_FLAGS =
-msvc: BOTAN_CXX_FLAGS += /wd4127 /wd4244 /wd4250 /wd4267 /wd4334 /wd4702 /wd4996
+msvc: BOTAN_CXX_FLAGS += /wd4127 /wd4244 /wd4250 /wd4267 /wd4334 /wd4702 /wd4996 \
+                         /D_ENABLE_EXTENDED_ALIGNED_STORAGE
 else: BOTAN_CXX_FLAGS += -Wno-unused-parameter
 macos: BOTAN_CXX_FLAGS += -mmacosx-version-min=$$QMAKE_MACOSX_DEPLOYMENT_TARGET -isysroot $$shell_quote($$QMAKE_MAC_SDK_PATH)
 unix: BOTAN_CXX_FLAGS += -fPIC
diff --git a/src/libs/botan/botan.qbs b/src/libs/botan/botan.qbs
index 3872e900adb..65aa6ebb96a 100644
--- a/src/libs/botan/botan.qbs
+++ b/src/libs/botan/botan.qbs
@@ -44,7 +44,7 @@ Product {
             var cxxFlags = [];
             if (product.qbs.toolchain.contains("msvc")) {
                 cxxFlags.push("/wd4127", "/wd4244", "/wd4250", "/wd4267", "/wd4334", "/wd4702",
-                              "/wd4996");
+                              "/wd4996", "/D_ENABLE_EXTENDED_ALIGNED_STORAGE");
             }
             else if (product.qbs.toolchain.contains("gcc"))
                 cxxFlags.push("-Wno-unused-parameter");