diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index 1feb28cfe557..8ca1767dafb6 100644
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -131,6 +131,20 @@ config EROFS_FS_ZIP_LZMA
 
 	  Say N if you want to disable LZMA compression support.
 
+config EROFS_FS_ZIP_LZMA_DEFAULT_MAX_STREAMS
+	int "EROFS LZMA default maximum decompression streams"
+	depends on EROFS_FS_ZIP_LZMA
+	range 1 NR_CPUS
+	default 16
+	help
+	  By default EROFS allocates one LZMA decompression stream per CPU.
+	  Each stream can hold a dictionary of up to 8 MiB taken from the
+	  mounted image, so on systems with many CPUs this can reserve a lot
+	  of memory.  This caps the default; the lzma_streams module parameter
+	  still overrides it.
+
+	  If unsure, keep the default of 16.
+
 config EROFS_FS_ZIP_DEFLATE
 	bool "EROFS DEFLATE compressed data support"
 	depends on EROFS_FS_ZIP
diff --git a/fs/erofs/decompressor_lzma.c b/fs/erofs/decompressor_lzma.c
index f6692d0f2f04..6b0cdb446c6a 100644
--- a/fs/erofs/decompressor_lzma.c
+++ b/fs/erofs/decompressor_lzma.c
@@ -51,7 +51,8 @@ static int __init z_erofs_lzma_init(void)
 
 	/* by default, use # of possible CPUs instead */
 	if (!z_erofs_lzma_nstrms)
-		z_erofs_lzma_nstrms = num_possible_cpus();
+		z_erofs_lzma_nstrms = min_t(unsigned int, num_possible_cpus(),
+				CONFIG_EROFS_FS_ZIP_LZMA_DEFAULT_MAX_STREAMS);
 
 	for (i = 0; i < z_erofs_lzma_nstrms; ++i) {
 		struct z_erofs_lzma *strm = kzalloc_obj(*strm);