diff --git a/libc/arch-x86/atom/string/sse2-memset-atom.S b/libc/arch-x86/atom/string/sse2-memset-atom.S
index e03cd1a..04de18f 100644
--- a/libc/arch-x86/atom/string/sse2-memset-atom.S
+++ b/libc/arch-x86/atom/string/sse2-memset-atom.S
@@ -117,8 +117,10 @@
 
   movl LEN(%esp), %ecx
   cmpl CHK_DST_LEN(%esp), %ecx
-  ja __memset_chk_fail
-  jmp L(memset_length_loaded)
+  jna L(memset_length_loaded)
+
+  POP (%ebx) // Undo ENTRANCE without returning.
+  jmp __memset_chk_fail
 END(__memset_chk)
 
 	.section .text.sse2,"ax",@progbits
diff --git a/libc/arch-x86/silvermont/string/sse2-memset-slm.S b/libc/arch-x86/silvermont/string/sse2-memset-slm.S
index f5182ba..f28e1b8 100644
--- a/libc/arch-x86/silvermont/string/sse2-memset-slm.S
+++ b/libc/arch-x86/silvermont/string/sse2-memset-slm.S
@@ -117,8 +117,10 @@
 
   movl LEN(%esp), %ecx
   cmpl CHK_DST_LEN(%esp), %ecx
-  ja __memset_chk_fail
-  jmp L(memset_length_loaded)
+  jna L(memset_length_loaded)
+
+  POP (%ebx) // Undo ENTRANCE without returning.
+  jmp __memset_chk_fail
 END(__memset_chk)
 
 	.section .text.sse2,"ax",@progbits