diff --git a/include/mbedtls/sha3.h b/include/mbedtls/sha3.h
index 36942db88..7d673bc91 100644
--- a/include/mbedtls/sha3.h
+++ b/include/mbedtls/sha3.h
@@ -145,9 +145,9 @@ int mbedtls_sha3_update( mbedtls_sha3_context *ctx,
  *                 and have a hash operation started.
  * \param output   The SHA-3 checksum result.
  *                 This must be a writable buffer of length \c olen bytes.
- * \param olen     Defines a variable output length (in bytes). \c output must be
- *                 \c olen bytes length. For SHA-3 224, SHA-3 256, SHA-3 384 and
- *                 SHA-3 512 must equal to 28, 32, 48 and 64, respectively.
+ * \param olen     Defines the length of output buffer (in bytes). For SHA-3 224, SHA-3 256,
+ *                 SHA-3 384 and SHA-3 512 \c olen must equal to 28, 32, 48 and 64,
+ *                 respectively.
  *
  * \return         \c 0 on success.
  * \return         A negative error code on failure.
@@ -171,8 +171,9 @@ int mbedtls_sha3_finish( mbedtls_sha3_context *ctx,
  * \param ilen     The length of the input data in Bytes.
  * \param output   The SHA-3 checksum result.
  *                 This must be a writable buffer of length \c olen bytes.
- * \param olen     Determines the length (in bytes) of the output. \c output
- *                 must be \c olen bytes length.
+ * \param olen     Defines the length of output buffer (in bytes). For SHA-3 224, SHA-3 256,
+ *                 SHA-3 384 and SHA-3 512 \c olen must equal to 28, 32, 48 and 64,
+ *                 respectively.
  *
  * \return         \c 0 on success.
  * \return         A negative error code on failure.
diff --git a/library/sha3.c b/library/sha3.c
index f5af2b7b8..9aadf9df7 100644
--- a/library/sha3.c
+++ b/library/sha3.c
@@ -244,8 +244,13 @@ int mbedtls_sha3_finish( mbedtls_sha3_context *ctx,
     if( ctx == NULL || output == NULL )
         return( MBEDTLS_ERR_SHA3_BAD_INPUT_DATA );
 
-    if( ctx->olen > 0 && ctx->olen != olen )
-        return( MBEDTLS_ERR_SHA3_BAD_INPUT_DATA );
+    /* Catch SHA-3 families, with fixed output length */
+    if( ctx->olen > 0 )
+    {
+        if ( ctx->olen > olen )
+            return( MBEDTLS_ERR_SHA3_BAD_INPUT_DATA );
+        olen = ctx->olen;
+    }
 
     ABSORB( ctx, ctx->index, ctx->xor_byte );
     ABSORB( ctx, ctx->max_block_size - 1, 0x80 );