diff --git a/browser/config/mozconfigs/win32/mingwclang b/browser/config/mozconfigs/win32/mingwclang
index f096e7874214..ae7c0eaac5ef 100644
--- a/browser/config/mozconfigs/win32/mingwclang
+++ b/browser/config/mozconfigs/win32/mingwclang
@@ -44,6 +44,7 @@ ac_add_options --enable-proxy-bypass-protection
 ac_add_options --disable-webrtc # Bug 1393901
 ac_add_options --disable-geckodriver # Bug 1489320
 ac_add_options --disable-update-agent # Bug 1561797
+ac_add_options --disable-default-browser-agent # WinToast does not build on mingw
 
 # Find our toolchain
 HOST_CC="$MOZ_FETCHES_DIR/clang/bin/clang"
diff --git a/browser/config/mozconfigs/win64/mingwclang b/browser/config/mozconfigs/win64/mingwclang
index 8121b086fc0c..ee134fe08cce 100755
--- a/browser/config/mozconfigs/win64/mingwclang
+++ b/browser/config/mozconfigs/win64/mingwclang
@@ -44,6 +44,7 @@ ac_add_options --enable-proxy-bypass-protection
 ac_add_options --disable-webrtc # Bug 1393901
 ac_add_options --disable-geckodriver # Bug 1489320
 ac_add_options --disable-update-agent # Bug 1561797
+ac_add_options --disable-default-browser-agent # WinToast does not build on mingw
 
 # Find our toolchain
 HOST_CC="$MOZ_FETCHES_DIR/clang/bin/clang"