diff --git a/package/janet/Config.in b/package/janet/Config.in
index 7b78c14bf4..bb4bf462aa 100644
--- a/package/janet/Config.in
+++ b/package/janet/Config.in
@@ -1,5 +1,6 @@
 config BR2_PACKAGE_JANET
 	bool "janet"
+	depends on BR2_USE_MMU # fork()
 	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_9 # C11/stdatomic.h
 	help
 	  Janet is a functional and imperative programming language.
@@ -11,4 +12,5 @@ config BR2_PACKAGE_JANET
 	  https://janet-lang.org/
 
 comment "janet needs a toolchain w/ gcc >= 4.9"
+	depends on BR2_USE_MMU
 	depends on !BR2_TOOLCHAIN_GCC_AT_LEAST_4_9