diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
@@ -5394,7 +5394,8 @@
   TypeSize WidthDiff = WidenWidth - LdWidth;
   // Allow wider loads if they are sufficiently aligned to avoid memory faults
   // and if the original load is simple.
-  unsigned LdAlign = (!LD->isSimple()) ? 0 : LD->getAlignment();
+  unsigned LdAlign =
+      (!LD->isSimple() || LdVT.isScalableVector()) ? 0 : LD->getAlignment();
 
   // Find the vector type that can load from.
   EVT NewVT = FindMemType(DAG, TLI, LdWidth.getKnownMinSize(), WidenVT, LdAlign,
diff --git a/llvm/test/CodeGen/RISCV/rvv/legalize-load-sdnode.ll b/llvm/test/CodeGen/RISCV/rvv/legalize-load-sdnode.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/rvv/legalize-load-sdnode.ll
@@ -0,0 +1,16 @@
+; RUN: not --crash llc -mtriple=riscv32 -mattr=+m,+experimental-v,+experimental-zfh,+f,+d -verify-machineinstrs < %s
+; RUN: not --crash llc -mtriple=riscv64 -mattr=+m,+experimental-v,+experimental-zfh,+f,+d -verify-machineinstrs < %s
+
+; Check that we are able to legalize scalable-vector loads that require widening.
+
+; FIXME: LLVM can't yet widen scalable-vector loads.
+
+define <vscale x 3 x i8> @load_nxv3i8(<vscale x 3 x i8>* %ptr) {
+  %v = load <vscale x 3 x i8>, <vscale x 3 x i8>* %ptr
+  ret <vscale x 3 x i8> %v
+}
+
+define <vscale x 5 x half> @load_nxv5f16(<vscale x 5 x half>* %ptr) {
+  %v = load <vscale x 5 x half>, <vscale x 5 x half>* %ptr
+  ret <vscale x 5 x half> %v
+}
diff --git a/llvm/test/CodeGen/RISCV/rvv/legalize-store-sdnode.ll b/llvm/test/CodeGen/RISCV/rvv/legalize-store-sdnode.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/rvv/legalize-store-sdnode.ll
@@ -0,0 +1,16 @@
+; RUN: not --crash llc -mtriple=riscv32 -mattr=+m,+experimental-v,+experimental-zfh,+f,+d -verify-machineinstrs < %s
+; RUN: not --crash llc -mtriple=riscv64 -mattr=+m,+experimental-v,+experimental-zfh,+f,+d -verify-machineinstrs < %s
+
+; Check that we are able to legalize scalable-vector stores that require widening.
+
+; FIXME: LLVM can't yet widen scalable-vector stores.
+
+define void @store_nxv3i8(<vscale x 3 x i8> %val, <vscale x 3 x i8>* %ptr) {
+  store <vscale x 3 x i8> %val, <vscale x 3 x i8>* %ptr
+  ret void
+}
+
+define void @store_nxv7f64(<vscale x 7 x double> %val, <vscale x 7 x double>* %ptr) {
+  store <vscale x 7 x double> %val, <vscale x 7 x double>* %ptr
+  ret void
+}