diff --git a/clients/cli/build/innosetup/Dockerfile b/clients/cli/build/innosetup/Dockerfile
index 8e850e464..1d341ae75 100644
--- a/clients/cli/build/innosetup/Dockerfile
+++ b/clients/cli/build/innosetup/Dockerfile
@@ -8,5 +8,9 @@ ENV WINEARCH win32
 ENV FORCE_COLOR 1
 
 # # Install Inno Setup binaries
-RUN curl -SL "http://www.jrsoftware.org/download.php/is.exe" -o is.exe
+# jrsoftware.org's old download.php shortcut no longer serves the binary
+# directly (it now returns an HTML landing page); pin to a specific release
+# from GitHub instead. Stick to the last unified (non x86/x64-split) build,
+# since WINEARCH is win32.
+RUN curl -SL "https://github.com/jrsoftware/issrc/releases/download/is-6_7_3/innosetup-6.7.3.exe" -o is.exe
 RUN xvfb-run wine is.exe /VERYSILENT /SUPPRESSMSGBOXES /NORESTART