diff --git a/app/vmselect/promql/rollup.go b/app/vmselect/promql/rollup.go
index be6ade1110..1c4946e752 100644
--- a/app/vmselect/promql/rollup.go
+++ b/app/vmselect/promql/rollup.go
@@ -1495,11 +1495,8 @@ func rollupDelta(rfa *rollupFuncArg) float64 {
 			// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/894
 			return values[len(values)-1] - rfa.realPrevValue
 		}
-		// Assume that the previous non-existing value was 0 only in the following cases:
-		//
-		// - If the delta with the next value equals to 0.
-		//   This is the case for slow-changing counter - see https://github.com/VictoriaMetrics/VictoriaMetrics/issues/962
-		// - If the first value doesn't exceed too much the delta with the next value.
+		// Assume that the previous non-existing value was 0
+		// only if the first value doesn't exceed too much the delta with the next value.
 		//
 		// This should prevent from improper increase() results for os-level counters
 		// such as cpu time or bytes sent over the network interface.
@@ -1513,9 +1510,6 @@ func rollupDelta(rfa *rollupFuncArg) float64 {
 		} else if !math.IsNaN(rfa.realNextValue) {
 			d = rfa.realNextValue - values[0]
 		}
-		if d == 0 {
-			d = 10
-		}
 		if math.Abs(values[0]) < 10*(math.Abs(d)+1) {
 			prevValue = 0
 		} else {
diff --git a/app/vmselect/promql/rollup_test.go b/app/vmselect/promql/rollup_test.go
index ae33628145..806398c1e5 100644
--- a/app/vmselect/promql/rollup_test.go
+++ b/app/vmselect/promql/rollup_test.go
@@ -1425,19 +1425,16 @@ func TestRollupDelta(t *testing.T) {
 
 	// Small initial value
 	f(nan, nan, nan, []float64{1}, 1)
-	f(nan, nan, nan, []float64{10}, 10)
-	f(nan, nan, nan, []float64{100}, 100)
+	f(nan, nan, nan, []float64{10}, 0)
+	f(nan, nan, nan, []float64{100}, 0)
 	f(nan, nan, nan, []float64{1, 2, 3}, 3)
 	f(1, nan, nan, []float64{1, 2, 3}, 2)
 	f(nan, nan, nan, []float64{5, 6, 8}, 8)
 	f(2, nan, nan, []float64{5, 6, 8}, 6)
 
-	// Moderate initial value with zero delta after that.
-	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/962
-	f(nan, nan, nan, []float64{100}, 100)
-	f(nan, nan, nan, []float64{100, 100}, 100)
+	f(nan, nan, nan, []float64{100, 100}, 0)
 
-	// Big initial value with with zero delta after that.
+	// Big initial value with zero delta after that.
 	f(nan, nan, nan, []float64{1000}, 0)
 	f(nan, nan, nan, []float64{1000, 1000}, 0)