diff --git a/src/main/java/com/clearfolio/viewer/analytics/KpiSnapshotLedger.java b/src/main/java/com/clearfolio/viewer/analytics/KpiSnapshotLedger.java
index f5cbde5d..29370df1 100644
--- a/src/main/java/com/clearfolio/viewer/analytics/KpiSnapshotLedger.java
+++ b/src/main/java/com/clearfolio/viewer/analytics/KpiSnapshotLedger.java
@@ -213,7 +213,11 @@ private static int integer(String field) {
 
     private static double rate(String field) {
         try {
-            return Double.parseDouble(field);
+            double value = Double.parseDouble(field);
+            if (!Double.isFinite(value) || value < 0.0 || value > 1.0) {
+                throw invalidLine();
+            }
+            return value;
         } catch (NumberFormatException ex) {
             throw invalidLine(ex);
         }
@@ -224,7 +228,11 @@ private static Long nullableLong(String field) {
             return null;
         }
         try {
-            return Long.parseLong(field);
+            long value = Long.parseLong(field);
+            if (value < 0L) {
+                throw invalidLine();
+            }
+            return value;
         } catch (NumberFormatException ex) {
             throw invalidLine(ex);
         }
diff --git a/src/test/java/com/clearfolio/viewer/analytics/KpiSnapshotLedgerTest.java b/src/test/java/com/clearfolio/viewer/analytics/KpiSnapshotLedgerTest.java
index d42349fd..a91f129e 100644
--- a/src/test/java/com/clearfolio/viewer/analytics/KpiSnapshotLedgerTest.java
+++ b/src/test/java/com/clearfolio/viewer/analytics/KpiSnapshotLedgerTest.java
@@ -82,7 +82,13 @@ void rejectsInvalidPersistedLedgerLines() throws Exception {
         assertInvalidLedger(snapshotLine().replace(NOW.toString(), "not-instant"));
         assertInvalidLedger(snapshotLine().replace("\t2\t", "\tnot-int\t"));
         assertInvalidLedger(snapshotLine().replace("\t0.5\t", "\tnot-rate\t"));
+        assertInvalidLedger(snapshotLine().replace("\t0.5\t", "\tNaN\t"));
+        assertInvalidLedger(snapshotLine().replace("\t0.5\t", "\tInfinity\t"));
+        assertInvalidLedger(snapshotLine().replace("\t0.5\t", "\t-Infinity\t"));
+        assertInvalidLedger(snapshotLine().replace("\t0.5\t", "\t-0.01\t"));
+        assertInvalidLedger(snapshotLine().replace("\t0.5\t", "\t1.01\t"));
         assertInvalidLedger(snapshotLine().replace("\t123", "\tnot-long"));
+        assertInvalidLedger(snapshotLine().replace("\t123", "\t-1"));
         assertInvalidLedger(snapshotLine().replace(encoded("tenant-a"), "!"));
     }