diff --git a/ssh-askpass b/ssh-askpass
index 4da060d..57e65a4 100755
--- a/ssh-askpass
+++ b/ssh-askpass
@@ -1,8 +1,34 @@
 #!/bin/sh
 # vim: set sw=4 ts=4 sts=4 et :
 
+pinentry() {
+    if [ -n "${TMUX}" ] && [ -z "${DISPLAY}" ]; then
+        # We're running in a TMUX pane, launch a new window to handle
+        # passphrase/confirmation prompt
+        unset t1 t2
+        mkfifo "${t1:=$(mktemp -u)}"
+        mkfifo "${t2:=$(mktemp -u)}"
+        tmux new-window sh -c "exec pinentry -T \$(tty) < '$t1' > '$t2'"
+        cat > "$t1"
+        cat "$t2"
+        rm -f "$t1" "$t2"
+        return
+    elif [ -n "${SSH_TTY}" ]; then
+        # We're in an SSH session, so prompt for the passphrase on the
+        # SSH client terminal
+        set -- -T "${SSH_TTY}" "$@"
+    elif [ -t 0 ]; then
+        set -- -T $(tty) "$@"
+    elif [ -t 1 ]; then
+        set -- -T $(tty <&1) "$@"
+    elif [ -t 2 ]; then
+        set -- -T $(tty <&2) "$@"
+    fi
+    command pinentry "$@"
+}
+
 prompt_confirm() {
-    result=$(pinentry -T $(tty) -g <<EOF | grep -E '^(D|ERR)'
+    result=$(pinentry -g <<EOF | grep -E '^(D|ERR)'
 SETTITLE ssh-askpass
 SETDESC $1
 SETOK Yes
@@ -26,7 +52,7 @@ EOF
 }
 
 prompt_notify() {
-    pinentry -T $(tty) -g <<EOF || :
+    pinentry -g <<EOF || :
 SETTITLE ssh-askpass
 SETDESC $1
 SETTIMEOUT 3
@@ -35,7 +61,7 @@ EOF
 }
 
 prompt_passphrase() {
-    result=$(pinentry -T $(tty) -g <<EOF | grep -E '^(D|ERR)'
+    result=$(pinentry -g <<EOF | grep -E '^(D|ERR)'
 SETTITLE ssh-askpass
 SETDESC $1
 SETPROMPT Passphrase: