diff --git a/sim/mcuboot-sys/Cargo.toml b/sim/mcuboot-sys/Cargo.toml
index 06f6aec..42daf2d 100644
--- a/sim/mcuboot-sys/Cargo.toml
+++ b/sim/mcuboot-sys/Cargo.toml
@@ -68,6 +68,10 @@
 # Support multiple images (currently 2 instead of 1).
 multiimage = []
 
+# Support simulation of ram-loading.  No swaps are performed, and the
+# image is copied to RAM before loading it.
+ram-load = []
+
 # Check (in software) against version downgrades.
 downgrade-prevention = []
 
diff --git a/sim/mcuboot-sys/build.rs b/sim/mcuboot-sys/build.rs
index 6f16f04..e4ceefc 100644
--- a/sim/mcuboot-sys/build.rs
+++ b/sim/mcuboot-sys/build.rs
@@ -30,6 +30,7 @@
     let bootstrap = env::var("CARGO_FEATURE_BOOTSTRAP").is_ok();
     let multiimage = env::var("CARGO_FEATURE_MULTIIMAGE").is_ok();
     let downgrade_prevention = env::var("CARGO_FEATURE_DOWNGRADE_PREVENTION").is_ok();
+    let ram_load = env::var("CARGO_FEATURE_RAM_LOAD").is_ok();
 
     let mut conf = cc::Build::new();
     conf.define("__BOOTSIM__", None);
@@ -56,6 +57,13 @@
         conf.define("MCUBOOT_DOWNGRADE_PREVENTION", None);
     }
 
+    if ram_load {
+        conf.define("MCUBOOT_RAM_LOAD", None);
+
+        conf.define("IMAGE_EXECUTABLE_RAM_START", "0x10000");
+        conf.define("IMAGE_EXECUTABLE_RAM_SIZE", "0x10000");
+    }
+
     // Currently no more than one sig type can be used simultaneously.
     if vec![sig_rsa, sig_rsa3072, sig_ecdsa, sig_ed25519].iter()
         .fold(0, |sum, &v| sum + v as i32) > 1 {