diff --git a/bin/build-helper b/bin/build-helper
index 5bde6cdf..f0f1ac8f 100755
--- a/bin/build-helper
+++ b/bin/build-helper
@@ -170,6 +170,7 @@ eof
         # gpg --verify <asc-file> <file>
         # gpg --no-default-keyring --keyring <pubkey.gpg> --verify <asc-file> <file>
         # Ensure gpg-agent is running.
+        export GPG_TTY=$(tty)
         gpg-agent
 
         git tag -s "$target_version" -m "$tagmessage"
diff --git a/bin/build-helper.freebsd b/bin/build-helper.freebsd
index 32677503..616c88b2 100755
--- a/bin/build-helper.freebsd
+++ b/bin/build-helper.freebsd
@@ -205,6 +205,7 @@ eof
         # gpg --verify <asc-file> <file>
         # gpg --no-default-keyring --keyring <pubkey.gpg> --verify <asc-file> <file>
         # Ensure gpg-agent is running.
+        export GPG_TTY=$(tty)
         gpg-agent
 
         git tag -s "$target_version" -m "$tagmessage"