diff --git a/src/liblzma/api/lzma/container.h b/src/liblzma/api/lzma/container.h
index b2b912d5..564c6aaf 100644
--- a/src/liblzma/api/lzma/container.h
+++ b/src/liblzma/api/lzma/container.h
@@ -73,7 +73,7 @@ typedef struct {
 	 *
 	 * Decoder: Bitwise-or of zero or more of the decoder flags:
 	 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
-	 * LZMA_TELL_ANY_CHECK, LZMA_CONCATENATED
+	 * LZMA_TELL_ANY_CHECK, LZMA_CONCATENATED, LZMA_FAIL_FAST
 	 */
 	uint32_t flags;
 
@@ -615,6 +615,29 @@ extern LZMA_API(lzma_ret) lzma_microlzma_encoder(
 #define LZMA_CONCATENATED               UINT32_C(0x08)
 
 
+/**
+ * This flag makes the threaded decoder report errors (like LZMA_DATA_ERROR)
+ * as soon as they are detected. This saves time when the application has no
+ * interest in a partially decompressed truncated or corrupt file. Note that
+ * due to timing randomness, if the same truncated or corrupt input is
+ * decompressed multiple times with this flag, a different amount of output
+ * may be produced by different runs, and even the error code might vary.
+ *
+ * Without this flag the threaded decoder will provide as much output as
+ * possible at first and then report the pending error. This default behavior
+ * matches the single-threaded decoder and provides repeatable behavior
+ * with truncated or corrupt input. There are a few special cases where the
+ * behavior can still differ like memory allocation failures (LZMA_MEM_ERROR).
+ *
+ * Single-threaded decoders currently ignore this flag.
+ *
+ * Support for this flag was added in liblzma 5.3.3alpha. Note that in older
+ * versions this flag isn't supported (LZMA_OPTIONS_ERROR) even by functions
+ * that ignore this flag in newer liblzma versions.
+ */
+#define LZMA_FAIL_FAST                  UINT32_C(0x20)
+
+
 /**
  * \brief       Initialize .xz Stream decoder
  *
diff --git a/src/liblzma/common/common.h b/src/liblzma/common/common.h
index 67996228..36366dbc 100644
--- a/src/liblzma/common/common.h
+++ b/src/liblzma/common/common.h
@@ -67,14 +67,15 @@
 #define LZMA_FILTER_RESERVED_START (LZMA_VLI_C(1) << 62)
 
 
-/// Supported flags that can be passed to lzma_stream_decoder()
-/// or lzma_auto_decoder().
+/// Supported flags that can be passed to lzma_stream_decoder(),
+/// lzma_auto_decoder(), or lzma_stream_decoder_mt().
 #define LZMA_SUPPORTED_FLAGS \
 	( LZMA_TELL_NO_CHECK \
 	| LZMA_TELL_UNSUPPORTED_CHECK \
 	| LZMA_TELL_ANY_CHECK \
 	| LZMA_IGNORE_CHECK \
-	| LZMA_CONCATENATED )
+	| LZMA_CONCATENATED \
+	| LZMA_FAIL_FAST )
 
 
 /// Largest valid lzma_action value as unsigned integer.
diff --git a/src/liblzma/common/stream_decoder_mt.c b/src/liblzma/common/stream_decoder_mt.c
index 7f445982..32e0b892 100644
--- a/src/liblzma/common/stream_decoder_mt.c
+++ b/src/liblzma/common/stream_decoder_mt.c
@@ -300,6 +300,10 @@ struct lzma_stream_coder {
 	/// Stream Padding is a multiple of four bytes.
 	bool concatenated;
 
+	/// If true, we will return any errors immediately instead of first
+	/// producing all output before the location of the error.
+	bool fail_fast;
+
 
 	/// When decoding concatenated Streams, this is true as long as we
 	/// are decoding the first Stream. This is needed to avoid misleading
@@ -711,13 +715,12 @@ read_output_and_wait(struct lzma_stream_coder *coder,
 					coder->pending_error
 							= coder->thread_error;
 
-				// FIXME? Add a flag to do this conditionally?
-				// That way errors would get reported to the
-				// application without a delay.
-// 				if (coder->fast_errors) {
-// 					ret = coder->thread_error;
-// 					break;
-// 				}
+				// If LZMA_FAIL_FAST was used, report errors
+				// from worker threads immediately.
+				if (coder->fail_fast) {
+					ret = coder->thread_error;
+					break;
+				}
 			}
 
 			// Check if decoding of the next Block can be started.
@@ -1690,22 +1693,24 @@ stream_decode_mt(void *coder_ptr, const lzma_allocator *allocator,
 		break;
 
 	case SEQ_ERROR:
-		// Let the application get all data before the point where
-		// the error was detected. This matches the behavior of
-		// single-threaded use.
-		//
-		// FIXME? Some errors (LZMA_MEM_ERROR) don't get here,
-		// they are returned immediately. Thus in rare cases the
-		// output will be less than in single-threaded mode. But
-		// maybe this doesn't matter much in practice.
-		return_if_error(read_output_and_wait(coder, allocator,
-				out, out_pos, out_size,
-				NULL, true, &wait_abs, &has_blocked));
+		if (!coder->fail_fast) {
+			// Let the application get all data before the point
+			// where the error was detected. This matches the
+			// behavior of single-threaded use.
+			//
+			// FIXME? Some errors (LZMA_MEM_ERROR) don't get here,
+			// they are returned immediately. Thus in rare cases
+			// the output will be less than in the single-threaded
+			// mode. Maybe this doesn't matter much in practice.
+			return_if_error(read_output_and_wait(coder, allocator,
+					out, out_pos, out_size,
+					NULL, true, &wait_abs, &has_blocked));
 
-		// We get here only if the error happened in the main thread,
-		// for example, unsupported Block Header.
-		if (!lzma_outq_is_empty(&coder->outq))
-			return LZMA_OK;
+			// We get here only if the error happened in the main
+			// thread, for example, unsupported Block Header.
+			if (!lzma_outq_is_empty(&coder->outq))
+				return LZMA_OK;
+		}
 
 		return coder->pending_error;
 
@@ -1900,6 +1905,7 @@ stream_decoder_mt_init(lzma_next_coder *next, const lzma_allocator *allocator,
 	coder->tell_any_check = (options->flags & LZMA_TELL_ANY_CHECK) != 0;
 	coder->ignore_check = (options->flags & LZMA_IGNORE_CHECK) != 0;
 	coder->concatenated = (options->flags & LZMA_CONCATENATED) != 0;
+	coder->fail_fast = (options->flags & LZMA_FAIL_FAST) != 0;
 
 	coder->first_stream = true;
 	coder->out_was_filled = false;