diff --git a/src/terminal/terminal.c b/src/terminal/terminal.c
index 67224659..5c688d61 100644
--- a/src/terminal/terminal.c
+++ b/src/terminal/terminal.c
@@ -1220,6 +1220,9 @@ int guac_terminal_resize(guac_terminal* terminal, int width, int height) {
     guac_client* client = display->client;
     guac_socket* socket = client->socket;
 
+    /* Acquire exclusive access to terminal */
+    guac_terminal_lock(terminal);
+
     /* Calculate available display area */
     int available_width = width - GUAC_TERMINAL_SCROLLBAR_WIDTH;
     if (available_width < 0)
@@ -1250,6 +1253,9 @@ int guac_terminal_resize(guac_terminal* terminal, int width, int height) {
 
     }
 
+    /* Release terminal */
+    guac_terminal_unlock(terminal);
+
     guac_terminal_notify(terminal);
     return 0;