diff --git a/crypto/riscv64cpuid.pl b/crypto/riscv64cpuid.pl
index 675e9b6111..5dcdc5c584 100644
--- a/crypto/riscv64cpuid.pl
+++ b/crypto/riscv64cpuid.pl
@@ -84,6 +84,22 @@ OPENSSL_cleanse:
 ___
 }
 
+{
+my ($ret) = ('a0');
+$code .= <<___;
+################################################################################
+# size_t riscv_vlen_asm(void)
+# Return VLEN (i.e. the length of a vector register in bits).
+.p2align 3
+.globl riscv_vlen_asm
+.type riscv_vlen_asm,\@function
+riscv_vlen_asm:
+    csrr $ret, vlenb
+    slli $ret, $ret, 3
+    ret
+.size riscv_vlen_asm,.-riscv_vlen_asm
+___
+}
 
 print $code;
 close STDOUT or die "error closing STDOUT: $!";
diff --git a/crypto/riscvcap.c b/crypto/riscvcap.c
index 1cbfb4a574..db75c21b28 100644
--- a/crypto/riscvcap.c
+++ b/crypto/riscvcap.c
@@ -17,9 +17,13 @@
 #define OPENSSL_RISCVCAP_IMPL
 #include "crypto/riscv_arch.h"
 
+extern size_t riscv_vlen_asm(void);
+
 static void parse_env(const char *envstr);
 static void strtoupper(char *str);
 
+static size_t vlen = 0;
+
 uint32_t OPENSSL_rdtsc(void)
 {
     return 0;
@@ -67,6 +71,11 @@ static void parse_env(const char *envstr)
     }
 }
 
+size_t riscv_vlen(void)
+{
+    return vlen;
+}
+
 # if defined(__GNUC__) && __GNUC__>=2
 __attribute__ ((constructor))
 # endif
@@ -81,6 +90,9 @@ void OPENSSL_cpuid_setup(void)
 
     if ((e = getenv("OPENSSL_riscvcap"))) {
         parse_env(e);
-        return;
+    }
+
+    if (RISCV_HAS_V()) {
+        vlen = riscv_vlen_asm();
     }
 }
diff --git a/include/crypto/riscv_arch.def b/include/crypto/riscv_arch.def
index 6c26dbf401..b355fa4ddc 100644
--- a/include/crypto/riscv_arch.def
+++ b/include/crypto/riscv_arch.def
@@ -32,6 +32,7 @@ RISCV_DEFINE_CAP(ZKSED, 0, 10)
 RISCV_DEFINE_CAP(ZKSH, 0, 11)
 RISCV_DEFINE_CAP(ZKR, 0, 12)
 RISCV_DEFINE_CAP(ZKT, 0, 13)
+RISCV_DEFINE_CAP(V, 0, 14)
 
 /*
  * In the future ...
diff --git a/include/crypto/riscv_arch.h b/include/crypto/riscv_arch.h
index 9518584111..8bd281ad80 100644
--- a/include/crypto/riscv_arch.h
+++ b/include/crypto/riscv_arch.h
@@ -61,4 +61,10 @@ static const size_t kRISCVNumCaps =
 #define RISCV_HAS_ZBKB_AND_ZKND_AND_ZKNE() (RISCV_HAS_ZBKB() && RISCV_HAS_ZKND() && RISCV_HAS_ZKNE())
 #define RISCV_HAS_ZKND_AND_ZKNE() (RISCV_HAS_ZKND() && RISCV_HAS_ZKNE())
 
+/*
+ * Get the size of a vector register in bits (VLEN).
+ * If RISCV_HAS_V() is false, then this returns 0.
+ */
+size_t riscv_vlen(void);
+
 #endif