diff --git a/sim/src/image.rs b/sim/src/image.rs
index 632dfa5..270ef24 100644
--- a/sim/src/image.rs
+++ b/sim/src/image.rs
@@ -689,6 +689,10 @@
         let mut fails = 0;
         let total_flash_ops = self.total_count.unwrap();
 
+        if skip_slow_test() {
+            return false;
+        }
+
         // Let's try an image halfway through.
         for i in 1 .. total_flash_ops {
             info!("Try interruption at {}", i);
@@ -775,6 +779,10 @@
 
         let mut fails = 0;
 
+        if skip_slow_test() {
+            return false;
+        }
+
         if self.is_swap_upgrade() {
             for i in 1 .. self.total_count.unwrap() {
                 info!("Try interruption at {}", i);
@@ -2314,3 +2322,14 @@
 fn test_alignments() -> &'static [usize] {
     &[32]
 }
+
+/// For testing, some of the tests are quite slow. This will query for an
+/// environment variable `MCUBOOT_SKIP_SLOW_TESTS`, which can be set to avoid
+/// running these tests.
+fn skip_slow_test() -> bool {
+    if let Ok(_) = std::env::var("MCUBOOT_SKIP_SLOW_TESTS") {
+        true
+    } else {
+        false
+    }
+}