diff --git a/scripts/ci/ci-driver.sh b/scripts/ci/ci-driver.sh
index 67a95a1f6115d89843cb3851a7e569fb77ff149c..f99e45e6f25a79483421c7691195df732b10d3fa 100755
--- a/scripts/ci/ci-driver.sh
+++ b/scripts/ci/ci-driver.sh
@@ -287,7 +287,7 @@ fi
 #############################################################################
 # Determine the version of Tor.
 
-TOR_VERSION=$(grep -m 1 AC_INIT configure.ac | sed -e 's/.*\[//; s/\].*//;')
+TOR_VERSION=$(grep -m 1 AC_INIT ${CI_SRCDIR}/configure.ac | sed -e 's/.*\[//; s/\].*//;')
 
 # Use variables like these when we need to behave differently depending on
 # Tor version.  Only create the variables we need.