diff --git a/src/terminal/terminal-handlers.c b/src/terminal/terminal-handlers.c
index cbdf922d1..e9de88f52 100644
--- a/src/terminal/terminal-handlers.c
+++ b/src/terminal/terminal-handlers.c
@@ -1309,7 +1309,7 @@ int guac_terminal_set_directory(guac_terminal* term, unsigned char c) {
     static char filename[2048];
     static int length = 0;
 
-    /* Stop on ECMA-48 ST (String Terminator */
+    /* Stop on ECMA-48 ST (String Terminator) */
     if (c == 0x9C || c == 0x5C || c == 0x07) {
         filename[length++] = '\0';
         term->char_handler = guac_terminal_echo;
@@ -1334,7 +1334,7 @@ int guac_terminal_download(guac_terminal* term, unsigned char c) {
     static char filename[2048];
     static int length = 0;
 
-    /* Stop on ECMA-48 ST (String Terminator */
+    /* Stop on ECMA-48 ST (String Terminator) */
     if (c == 0x9C || c == 0x5C || c == 0x07) {
         filename[length++] = '\0';
         term->char_handler = guac_terminal_echo;
@@ -1456,7 +1456,7 @@ int guac_terminal_window_title(guac_terminal* term, unsigned char c) {
 
     guac_socket* socket = term->client->socket;
 
-    /* Stop on ECMA-48 ST (String Terminator */
+    /* Stop on ECMA-48 ST (String Terminator) */
     if (c == 0x9C || c == 0x5C || c == 0x07) {
 
         /* Terminate and reset stored title */
@@ -1552,7 +1552,7 @@ int guac_terminal_xterm_palette(guac_terminal* term, unsigned char c) {
 
     }
 
-    /* Stop on ECMA-48 ST (String Terminator */
+    /* Stop on ECMA-48 ST (String Terminator) */
     if (c == 0x9C || c == 0x5C || c == 0x07)
         term->char_handler = guac_terminal_echo;
 
@@ -1560,6 +1560,14 @@ int guac_terminal_xterm_palette(guac_terminal* term, unsigned char c) {
 
 }
 
+int guac_terminal_unknown_osc(guac_terminal* term, unsigned char c) {
+    /* Stop on ECMA-48 ST (String Terminator) */
+    if (c == 0x9C || c == 0x5C || c == 0x07)
+        term->char_handler = guac_terminal_echo;
+
+    return 0;
+}
+
 int guac_terminal_osc(guac_terminal* term, unsigned char c) {
 
     static int operation = 0;
@@ -1599,12 +1607,16 @@ int guac_terminal_osc(guac_terminal* term, unsigned char c) {
         else if (operation == 4)
             term->char_handler = guac_terminal_xterm_palette;
 
+        /* Unknown OSC */
+        else
+            term->char_handler = guac_terminal_unknown_osc;
+
         /* Reset parameter for next OSC */
         operation = 0;
 
     }
 
-    /* Stop on ECMA-48 ST (String Terminator */
+    /* Stop on ECMA-48 ST (String Terminator) */
     else if (c == 0x9C || c == 0x5C || c == 0x07)
         term->char_handler = guac_terminal_echo;
 
diff --git a/src/terminal/terminal/terminal-handlers.h b/src/terminal/terminal/terminal-handlers.h
index 2f9b547c8..c3ddb4761 100644
--- a/src/terminal/terminal/terminal-handlers.h
+++ b/src/terminal/terminal/terminal-handlers.h
@@ -185,6 +185,21 @@ int guac_terminal_window_title(guac_terminal* term, unsigned char c);
  */
 int guac_terminal_xterm_palette(guac_terminal* term, unsigned char c);
 
+/**
+ * Handles the remaining characters of an unrecognized OSC sequence, discarding
+ * them until the sequence is terminated. OSC sequences are terminated by either
+ * the ECMA-48 String Terminator (ST), which may appear as ESC \ (0x1B 0x5C),
+ * the single-character ST (0x9C), or BEL (0x07). This handler is used when the
+ * OSC operation code is not recognized by the terminal emulator.
+ *
+ * @param term
+ *     The terminal that received the given character of data.
+ *
+ * @param c
+ *     The character that was received by the given terminal.
+ */
+int guac_terminal_unknown_osc(guac_terminal* term, unsigned char c);
+
 /**
  * Handles the remaining characters of an Operating System Code (OSC) sequence,
  * typically initiated with "ESC ]".