Index: head/lib/libc/mips/string/strchr.S
===================================================================
--- head/lib/libc/mips/string/strchr.S
+++ head/lib/libc/mips/string/strchr.S
@@ -44,7 +44,12 @@
 	.abicalls
 #endif
 
+/*
+ * char *
+ * strchr(const char *s, int c);
+ */
 LEAF(strchr)
+	and		a1, a1, 0xff
 1:
 	lbu		a2, 0(a0)		# get a byte
 	PTR_ADDU	a0, a0, 1
Index: head/lib/libc/mips/string/strrchr.S
===================================================================
--- head/lib/libc/mips/string/strrchr.S
+++ head/lib/libc/mips/string/strrchr.S
@@ -44,8 +44,13 @@
 	.abicalls
 #endif
 
+/*
+ * char *
+ * strrchr(const char *s, int c);
+ */
 LEAF(strrchr)
 	move		v0, zero		# default if not found
+	and		a1, a1, 0xff
 1:
 	lbu		a3, 0(a0)		# get a byte
 	PTR_ADDU	a0, a0, 1