diff --git a/kernel/mips64/asum.S b/kernel/mips64/asum.S
index 2bf95c65d2..4e75529f52 100644
--- a/kernel/mips64/asum.S
+++ b/kernel/mips64/asum.S
@@ -73,6 +73,7 @@
 	MTC	$0,  s1
 
 	MTC	$0,  s2
+	blez	INCX, .L999
 	dsll	INCX, INCX, BASE_SHIFT
 
 	blez	N, .L999
diff --git a/kernel/mips64/sum.S b/kernel/mips64/sum.S
index 261630d49d..725346ff62 100644
--- a/kernel/mips64/sum.S
+++ b/kernel/mips64/sum.S
@@ -73,6 +73,7 @@
 	MTC	$0,  s1
 
 	MTC	$0,  s2
+	blez	INCX, .L999
 	dsll	INCX, INCX, BASE_SHIFT
 
 	blez	N, .L999
diff --git a/kernel/mips64/zasum.S b/kernel/mips64/zasum.S
index cd22f98414..a7af6918da 100644
--- a/kernel/mips64/zasum.S
+++ b/kernel/mips64/zasum.S
@@ -73,6 +73,7 @@
 	MTC	$0,  s1
 
 	MTC	$0,  s2
+	blez    INCX, .L999
 	dsll	INCX, INCX, ZBASE_SHIFT
 
 	blez	N, .L999
diff --git a/kernel/mips64/zsum.S b/kernel/mips64/zsum.S
index 129b97900e..83c5393197 100644
--- a/kernel/mips64/zsum.S
+++ b/kernel/mips64/zsum.S
@@ -73,6 +73,7 @@
 	MTC	$0,  s1
 
 	MTC	$0,  s2
+	blez    INCX, .L999
 	dsll	INCX, INCX, ZBASE_SHIFT
 
 	blez	N, .L999