diff --git a/contrib/build-wine/build-electrum-git.sh b/contrib/build-wine/build-electrum-git.sh
index 07f610f18..cce7e38e9 100755
--- a/contrib/build-wine/build-electrum-git.sh
+++ b/contrib/build-wine/build-electrum-git.sh
@@ -56,7 +56,7 @@ rm -rf dist/
 
 # build standalone and portable versions
 info "Running pyinstaller..."
-ELECTRUM_CMDLINE_NAME="$NAME_ROOT-$VERSION" wine "$WINE_PYHOME/scripts/pyinstaller.exe" --noconfirm --ascii --clean -w deterministic.spec
+ELECTRUM_CMDLINE_NAME="$NAME_ROOT-$VERSION" wine "$WINE_PYHOME/scripts/pyinstaller.exe" --noconfirm --ascii --clean deterministic.spec
 
 # set timestamps in dist, in order to make the installer reproducible
 pushd dist
diff --git a/contrib/build-wine/make_win.sh b/contrib/build-wine/make_win.sh
index 6cda8dcab..dc3151254 100755
--- a/contrib/build-wine/make_win.sh
+++ b/contrib/build-wine/make_win.sh
@@ -31,7 +31,7 @@ export DLL_TARGET_DIR="$CACHEDIR/dlls"
 export WINEPREFIX="/opt/wine64"
 export WINEDEBUG=-all
 export WINE_PYHOME="c:/python3"
-export WINE_PYTHON="wine $WINE_PYHOME/python.exe -OO -B"
+export WINE_PYTHON="wine $WINE_PYHOME/python.exe -B"
 
 . "$CONTRIB"/build_tools_util.sh
 
diff --git a/contrib/build-wine/prepare-wine.sh b/contrib/build-wine/prepare-wine.sh
index f4042f162..a65945983 100755
--- a/contrib/build-wine/prepare-wine.sh
+++ b/contrib/build-wine/prepare-wine.sh
@@ -1,8 +1,8 @@
 #!/bin/bash
 
 PYINSTALLER_REPO="https://github.com/pyinstaller/pyinstaller.git"
-PYINSTALLER_COMMIT="0fe956a2c6157e1b276819de1a050c242de70a29"
-# ^ latest commit from "v4" branch, somewhat after "4.10" tag
+PYINSTALLER_COMMIT="413cce49ff28d87fad4472f4953489226ec90c84"
+# ^ tag "v5.11.0"
 
 PYTHON_VERSION=3.10.11
 
@@ -69,7 +69,7 @@ info "Building PyInstaller."
     else
         fail "unexpected WIN_ARCH: $WIN_ARCH"
     fi
-    if [ -f "$CACHEDIR/pyinstaller/PyInstaller/bootloader/Windows-$PYINST_ARCH/runw.exe" ]; then
+    if [ -f "$CACHEDIR/pyinstaller/PyInstaller/bootloader/Windows-$PYINST_ARCH-intel/runw.exe" ]; then
         info "pyinstaller already built, skipping"
         exit 0
     fi
@@ -94,7 +94,7 @@ info "Building PyInstaller."
                       CFLAGS="-static"
     popd
     # sanity check bootloader is there:
-    [[ -e "PyInstaller/bootloader/Windows-$PYINST_ARCH/runw.exe" ]] || fail "Could not find runw.exe in target dir!"
+    [[ -e "PyInstaller/bootloader/Windows-$PYINST_ARCH-intel/runw.exe" ]] || fail "Could not find runw.exe in target dir!"
 ) || fail "PyInstaller build failed"
 info "Installing PyInstaller."
 $WINE_PYTHON -m pip install --no-build-isolation --no-dependencies --no-warn-script-location ./pyinstaller
diff --git a/electrum/ecc_fast.py b/electrum/ecc_fast.py
index ba75498f2..a27e21149 100644
--- a/electrum/ecc_fast.py
+++ b/electrum/ecc_fast.py
@@ -148,7 +148,7 @@ except BaseException as e:
 
 if _libsecp256k1 is None:
     # hard fail:
-    sys.exit(f"Error: Failed to load libsecp256k1.")
+    raise ImportError("Failed to load libsecp256k1")
 
 
 def version_info() -> dict: