diff --git a/polmon.cc b/polmon.cc
index 29de476..3f85903 100644
--- a/polmon.cc
+++ b/polmon.cc
@@ -54,12 +54,14 @@ uint8_t getc() {
 
 void putc(uint8_t c) {
     asm volatile (
+            "push %%bp          \n\t"
             "movb %0, %%al      \n\t"
             "movb $0x0e, %%ah   \n\t"
             "movb $0, %%bh      \n\t"
             "int $0x10          \n\t"
+            "pop %%bp           \n\t"
             :: "r" (c)
-            : "ax", "bh", "cc", "bp"
+            : "ax", "bh", "cc"
             );
 }