diff --git a/src/hash/crc32/crc32_s390x.go b/src/hash/crc32/crc32_s390x.go
index 2f20690389..befb58f55f 100644
--- a/src/hash/crc32/crc32_s390x.go
+++ b/src/hash/crc32/crc32_s390x.go
@@ -4,14 +4,9 @@
 
 package crc32
 
-import (
-	"unsafe"
-)
-
 const (
 	vxMinLen    = 64
-	vxAlignment = 16
-	vxAlignMask = vxAlignment - 1
+	vxAlignMask = 15 // align to 16 bytes
 )
 
 // hasVectorFacility reports whether the machine has the z/Architecture
@@ -49,20 +44,13 @@ func genericIEEE(crc uint32, p []byte) uint32 {
 	return update(crc, IEEETable, p)
 }
 
-// updateCastagnoli calculates the checksum of p using genericCastagnoli to
-// align the data appropriately for vectorCastagnoli. It avoids using
-// vectorCastagnoli entirely if the length of p is less than or equal to
-// vxMinLen.
+// updateCastagnoli calculates the checksum of p using
+// vectorizedCastagnoli if possible and falling back onto
+// genericCastagnoli as needed.
 func updateCastagnoli(crc uint32, p []byte) uint32 {
 	// Use vectorized function if vector facility is available and
 	// data length is above threshold.
-	if hasVX && len(p) > vxMinLen {
-		pAddr := uintptr(unsafe.Pointer(&p[0]))
-		if pAddr&vxAlignMask != 0 {
-			prealign := vxAlignment - int(pAddr&vxAlignMask)
-			crc = genericCastagnoli(crc, p[:prealign])
-			p = p[prealign:]
-		}
+	if hasVX && len(p) >= vxMinLen {
 		aligned := len(p) & ^vxAlignMask
 		crc = vectorizedCastagnoli(crc, p[:aligned])
 		p = p[aligned:]
@@ -75,19 +63,12 @@ func updateCastagnoli(crc uint32, p []byte) uint32 {
 	return genericCastagnoli(crc, p)
 }
 
-// updateIEEE calculates the checksum of p using genericIEEE to align the data
-// appropriately for vectorIEEE. It avoids using vectorIEEE entirely if the length
-// of p is less than or equal to vxMinLen.
+// updateIEEE calculates the checksum of p using vectorizedIEEE if
+// possible and falling back onto genericIEEE as needed.
 func updateIEEE(crc uint32, p []byte) uint32 {
 	// Use vectorized function if vector facility is available and
 	// data length is above threshold.
-	if hasVX && len(p) > vxMinLen {
-		pAddr := uintptr(unsafe.Pointer(&p[0]))
-		if pAddr&vxAlignMask != 0 {
-			prealign := vxAlignment - int(pAddr&vxAlignMask)
-			crc = genericIEEE(crc, p[:prealign])
-			p = p[prealign:]
-		}
+	if hasVX && len(p) >= vxMinLen {
 		aligned := len(p) & ^vxAlignMask
 		crc = vectorizedIEEE(crc, p[:aligned])
 		p = p[aligned:]
diff --git a/src/hash/crc32/crc32_s390x.s b/src/hash/crc32/crc32_s390x.s
index f8d39f3df9..0b830531f7 100644
--- a/src/hash/crc32/crc32_s390x.s
+++ b/src/hash/crc32/crc32_s390x.s
@@ -128,6 +128,10 @@ TEXT vectorizedBody<>(SB),NOSPLIT,$0
 	VZERO   V0
 	VLVGF   $3, R2, V0
 
+	// Crash if the input size is less than 64-bytes.
+	CMP     R4, $64
+	BLT     crash
+
 	// Load a 64-byte data chunk and XOR with CRC
 	VLM     0(R3), V1, V4    // 64-bytes into V1..V4
 
@@ -243,3 +247,6 @@ done:
 	XOR     $0xffffffff, R2 // NOTW R2
 	MOVWZ   R2, ret + 32(FP)
 	RET
+
+crash:
+	MOVD    $0, (R0) // input size is less than 64-bytes