diff --git a/crypto/cipher/asm/chacha20_poly1305_x86_64.pl b/crypto/cipher/asm/chacha20_poly1305_x86_64.pl
index 1d4bbcbf..af303b97 100644
--- a/crypto/cipher/asm/chacha20_poly1305_x86_64.pl
+++ b/crypto/cipher/asm/chacha20_poly1305_x86_64.pl
@@ -138,7 +138,7 @@ $code.="mov 0+$r_store, %rax
         mov %rdx, $t1
         mov 0+$r_store, %rax
         mul $acc1
-        imul $acc2, $t2
+        imulq $acc2, $t2
         add %rax, $t1
         adc %rdx, $t2\n";
 }
@@ -157,7 +157,7 @@ $code.="mov 8+$r_store, %rax
 }
 
 sub poly_stage3 {
-$code.="imul $acc2, $t3
+$code.="imulq $acc2, $t3
         add $acc0, $t2
         adc %rdx, $t3\n";
 }
@@ -1378,7 +1378,7 @@ $code.=<<___;
     mov %rdx, $t2
     mulx $acc0, $t0, $t1
     mulx $acc1, %rax, %rdx
-    imul $acc2, $t2
+    imulq $acc2, $t2
     add %rax, $t1
     adc %rdx, $t2
 ___
@@ -1392,7 +1392,7 @@ $code.=<<___;
     mulx $acc1, $acc1, $t3
     adc $acc1, $t2
     adc \$0, $t3
-    imul $acc2, %rdx
+    imulq $acc2, %rdx
 ___
 }