diff --git a/llvm/lib/Target/RISCV/RISCVTargetMachine.cpp b/llvm/lib/Target/RISCV/RISCVTargetMachine.cpp
--- a/llvm/lib/Target/RISCV/RISCVTargetMachine.cpp
+++ b/llvm/lib/Target/RISCV/RISCVTargetMachine.cpp
@@ -111,6 +111,9 @@
   // RISC-V supports the MachineOutliner.
   setMachineOutliner(true);
   setSupportsDefaultOutlining(true);
+
+  if (TT.isOSFuchsia() && !TT.isArch64Bit())
+    report_fatal_error("Fuchsia is only supported for 64-bit");
 }
 
 const RISCVSubtarget *
diff --git a/llvm/test/CodeGen/RISCV/rv32-fuchsia.ll b/llvm/test/CodeGen/RISCV/rv32-fuchsia.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/rv32-fuchsia.ll
@@ -0,0 +1,6 @@
+; RUN: not --crash llc -mtriple=riscv32-unknown-fuchsia < %s 2>&1 | FileCheck %s
+
+; CHECK: LLVM ERROR: Fuchsia is only supported for 64-bit
+define void @nothing() nounwind {
+  ret void
+}