diff --git a/clang/test/Driver/riscv-arch.c b/clang/test/Driver/riscv-arch.c
--- a/clang/test/Driver/riscv-arch.c
+++ b/clang/test/Driver/riscv-arch.c
@@ -258,6 +258,11 @@
 // RV32-STD: error: invalid arch name 'rv32imqc',
 // RV32-STD: unsupported standard user-level extension 'q'
 
+// RUN: %clang --target=riscv32-unknown-elf -march=rv32ib -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-B %s
+// RV32-B: error: invalid arch name 'rv32ib',
+// RV32-B: unsupported standard user-level extension 'b'
+
 // RUN: %clang --target=riscv32-unknown-elf -march=rv32xabc -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32X %s
 // RV32X: error: invalid arch name 'rv32xabc',
diff --git a/llvm/lib/Support/RISCVISAInfo.cpp b/llvm/lib/Support/RISCVISAInfo.cpp
--- a/llvm/lib/Support/RISCVISAInfo.cpp
+++ b/llvm/lib/Support/RISCVISAInfo.cpp
@@ -602,8 +602,8 @@
 
     // The order is OK, then push it into features.
     // TODO: Use version number when setting target features
-    // Currently LLVM supports only "mafdcbv".
-    StringRef SupportedStandardExtension = "mafdcbv";
+    // Currently LLVM supports only "mafdcv".
+    StringRef SupportedStandardExtension = "mafdcv";
     if (!SupportedStandardExtension.contains(C))
       return createStringError(errc::invalid_argument,
                                "unsupported standard user-level extension '%c'",