diff --git a/README.md b/README.md
index 960edbd..2ff88d0 100644
--- a/README.md
+++ b/README.md
@@ -37,6 +37,12 @@ bash test/run.sh --no-build      # reuse an already built image
 bash test/run.sh --suite compat  # run a single suite
 ```
 
+They run unchanged on Linux, macOS and Windows/Git-Bash. On Git-Bash the
+scripts set `MSYS_NO_PATHCONV=1` and `MSYS2_ARG_CONV_EXCL='*'` themselves,
+because MSYS would otherwise rewrite container paths such as
+`/usr/bin/backup` into `C:/Program Files/Git/usr/bin/backup` before `docker`
+sees them. Nothing has to be exported by hand.
+
 There are three suites:
 
 * **compat** (`test/compat.sh`) - backup, restore, forget, check, hooks and
diff --git a/test/lib.sh b/test/lib.sh
index 71d6fc1..5acc01b 100644
--- a/test/lib.sh
+++ b/test/lib.sh
@@ -4,6 +4,15 @@
 # Deliberately dependency-free: bash + docker only. No test framework, no
 # host-side bind mounts (files are moved with `docker cp`) so the suites behave
 # identically on Linux CI runners, macOS and Windows/Git-Bash.
+#
+# Windows/Git-Bash needs one extra thing: MSYS rewrites every argument that
+# looks like a POSIX path before the process sees it, so
+# `docker exec <id> /usr/bin/backup` reaches the daemon as
+# `C:/Program Files/Git/usr/bin/backup` and the container command is not found.
+# Both variables are required (one covers the command, one covers its
+# arguments) and both are ignored on Linux and macOS.
+export MSYS_NO_PATHCONV=1
+export MSYS2_ARG_CONV_EXCL='*'
 
 IMAGE="${IMAGE:-restic-backup-docker:test}"
 
diff --git a/test/run.sh b/test/run.sh
index 5295f1b..0cba1a6 100644
--- a/test/run.sh
+++ b/test/run.sh
@@ -12,6 +12,14 @@
 
 set -u
 
+# Windows/Git-Bash: MSYS mangles POSIX-looking arguments on their way to the
+# docker daemon, which breaks `docker exec` and `--config /test/structure.yml`.
+# lib.sh exports the same two variables for the suites that source it; run.sh
+# calls docker itself and starts the suites as separate processes, so it needs
+# them as well. Both are ignored on Linux and macOS.
+export MSYS_NO_PATHCONV=1
+export MSYS2_ARG_CONV_EXCL='*'
+
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 ROOT_DIR="$(cd "${SCRIPT_DIR}/.." && pwd)"
 IMAGE="${IMAGE:-restic-backup-docker:test}"