diff --git a/src/runtime.rs b/src/runtime.rs
index 3d27a712..b3eb74cf 100644
--- a/src/runtime.rs
+++ b/src/runtime.rs
@@ -8,6 +8,7 @@ use rustc_hash::{FxHashMap, FxHasher};
 use smallvec::SmallVec;
 use std::fmt::Write;
 use std::hash::BuildHasherDefault;
+use std::num::NonZeroU64;
 use std::sync::atomic::{AtomicU64, AtomicUsize, Ordering};
 use std::sync::Arc;
 
@@ -154,17 +155,13 @@ where
     /// Read current value of the revision counter.
     #[inline]
     pub(crate) fn current_revision(&self) -> Revision {
-        Revision {
-            generation: self.shared_state.revision.load(Ordering::SeqCst),
-        }
+        Revision::from(self.shared_state.revision.load(Ordering::SeqCst))
     }
 
     /// Read current value of the revision counter.
     #[inline]
     fn pending_revision(&self) -> Revision {
-        Revision {
-            generation: self.shared_state.pending_revision.load(Ordering::SeqCst),
-        }
+        Revision::from(self.shared_state.pending_revision.load(Ordering::SeqCst))
     }
 
     /// Check if the current revision is canceled. If this method ever
@@ -286,9 +283,7 @@ where
         let old_revision = self.shared_state.revision.fetch_add(1, Ordering::SeqCst);
         assert_eq!(current_revision, old_revision);
 
-        let new_revision = Revision {
-            generation: current_revision + 1,
-        };
+        let new_revision = Revision::from(current_revision + 1);
 
         debug!("increment_revision: incremented to {:?}", new_revision);
 
@@ -517,7 +512,7 @@ impl<DB: Database> ActiveQuery<DB> {
             database_key,
             changed_at: ChangedAt {
                 is_constant: true,
-                revision: Revision::START,
+                revision: Revision::start(),
             },
             dependencies: Some(FxIndexSet::default()),
         }
@@ -563,16 +558,22 @@ pub struct RuntimeId {
 /// directly as a user of salsa.
 #[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct Revision {
-    generation: u64,
+    generation: NonZeroU64,
 }
 
 impl Revision {
-    pub(crate) const START: Self = Revision { generation: 1 };
+    fn start() -> Self {
+        Self::from(1)
+    }
+
+    fn from(g: u64) -> Self {
+        Self {
+            generation: NonZeroU64::new(g).unwrap(),
+        }
+    }
 
     fn next(self) -> Revision {
-        Revision {
-            generation: self.generation + 1,
-        }
+        Self::from(self.generation.get() + 1)
     }
 }