diff --git a/backend/library.c b/backend/library.c
index 7ee64cf7..56125c23 100644
--- a/backend/library.c
+++ b/backend/library.c
@@ -1079,7 +1079,8 @@ int ZBarcode_Encode(struct zint_symbol *symbol, const unsigned char *source, int
         local_source[in_length] = '\0';
     }
 
-    if (symbol->input_mode &= ESCAPE_MODE) {
+    if (symbol->input_mode & ESCAPE_MODE) {
+        printf("Esc process\n");
         error_number = escape_char_process(symbol, local_source, &in_length);
         if (error_number != 0) {
             return error_number;
diff --git a/frontend/main.c b/frontend/main.c
index befa7a0d..af76792b 100644
--- a/frontend/main.c
+++ b/frontend/main.c
@@ -627,7 +627,7 @@ int main(int argc, char **argv) {
                     }
                 }
                 if (!strcmp(long_options[option_index].name, "esc")) {
-                    if (!(my_symbol->input_mode &= ESCAPE_MODE)) {
+                    if (!(my_symbol->input_mode & ESCAPE_MODE)) {
                         my_symbol->input_mode += ESCAPE_MODE;
                     }
                 }