diff --git a/libraries/stdlib/samples/test/samples/time/durations.kt b/libraries/stdlib/samples/test/samples/time/durations.kt
index 532b320c28a..92dd63f50e3 100644
--- a/libraries/stdlib/samples/test/samples/time/durations.kt
+++ b/libraries/stdlib/samples/test/samples/time/durations.kt
@@ -30,7 +30,7 @@ class Durations {
         assertPrints(Duration.minutes(1230), "20h 30m")
         assertPrints(Duration.minutes(920), "15h 20m")
         assertPrints(Duration.seconds(1.546), "1.546s")
-        assertPrints(Duration.milliseconds(25.12), "25.120ms")
+        assertPrints(Duration.milliseconds(25.12), "25.12ms")
     }
 
     @Sample
diff --git a/libraries/stdlib/src/kotlin/time/Duration.kt b/libraries/stdlib/src/kotlin/time/Duration.kt
index aa26d08072a..f35d9bcb0e0 100644
--- a/libraries/stdlib/src/kotlin/time/Duration.kt
+++ b/libraries/stdlib/src/kotlin/time/Duration.kt
@@ -748,11 +748,11 @@ public value class Duration internal constructor(private val rawValue: Long) : C
                             if (components++ > 0) append(' ')
                             when {
                                 seconds != 0 || hasDays || hasHours || hasMinutes ->
-                                    appendFractional(seconds, nanoseconds, "s")
+                                    appendFractional(seconds, nanoseconds, 9, "s", isoZeroes = false)
                                 nanoseconds >= 1_000_000 ->
-                                    appendFractional(nanoseconds / 1_000_000, nanoseconds % 1_000_000 * 1_000, "ms")
+                                    appendFractional(nanoseconds / 1_000_000, nanoseconds % 1_000_000, 6, "ms", isoZeroes = false)
                                 nanoseconds >= 1_000 ->
-                                    appendFractional(nanoseconds / 1_000, nanoseconds % 1_000 * 1_000_000, "us")
+                                    appendFractional(nanoseconds / 1_000, nanoseconds % 1_000, 3, "us", isoZeroes = false)
                                 else ->
                                     append(nanoseconds).append("ns")
                             }
@@ -764,15 +764,15 @@ public value class Duration internal constructor(private val rawValue: Long) : C
         }
     }
 
-    private fun StringBuilder.appendFractional(whole: Int, nanoFractional: Int, unit: String) {
+    private fun StringBuilder.appendFractional(whole: Int, fractional: Int, fractionalSize: Int, unit: String, isoZeroes: Boolean) {
         append(whole)
-        if (nanoFractional != 0) {
+        if (fractional != 0) {
             append('.')
-            val nanoString = nanoFractional.toString().padStart(9, '0')
+            val fracString = fractional.toString().padStart(fractionalSize, '0')
+            val nonZeroDigits = fracString.indexOfLast { it != '0' } + 1
             when {
-                nanoFractional % 1_000_000 == 0 -> appendRange(nanoString, 0, 3)
-                nanoFractional % 1_000 == 0 -> appendRange(nanoString, 0, 6)
-                else -> append(nanoString)
+                !isoZeroes && nonZeroDigits < 3 -> appendRange(fracString, 0, nonZeroDigits)
+                else -> appendRange(fracString, 0, ((nonZeroDigits + 2) / 3) * 3)
             }
         }
         append(unit)
@@ -836,7 +836,7 @@ public value class Duration internal constructor(private val rawValue: Long) : C
                 append(minutes).append('M')
             }
             if (hasSeconds || (!hasHours && !hasMinutes)) {
-                appendFractional(seconds, nanoseconds, "S")
+                appendFractional(seconds, nanoseconds, 9, "S", isoZeroes = true)
             }
         }
     }
diff --git a/libraries/stdlib/test/time/DurationTest.kt b/libraries/stdlib/test/time/DurationTest.kt
index cf18376af15..8d7aa273c02 100644
--- a/libraries/stdlib/test/time/DurationTest.kt
+++ b/libraries/stdlib/test/time/DurationTest.kt
@@ -626,24 +626,24 @@ class DurationTest {
         test(Duration.minutes(17.5), "17m 30s")
 
         test(Duration.minutes(16.5), "16m 30s")
-        test(Duration.seconds(1097.1), "18m 17.100s")
-        test(Duration.seconds(90.36), "1m 30.360s")
+        test(Duration.seconds(1097.1), "18m 17.1s")
+        test(Duration.seconds(90.36), "1m 30.36s")
         test(Duration.seconds(50), "50s")
-        test(Duration.seconds(1.3), "1.300s")
+        test(Duration.seconds(1.3), "1.3s")
         test(Duration.seconds(1), "1s")
 
         test(Duration.seconds(0.5), "500ms")
-        test(Duration.milliseconds(40.2), "40.200ms")
+        test(Duration.milliseconds(40.2), "40.2ms")
         test(Duration.milliseconds(4.225), "4.225ms")
         test(Duration.milliseconds(4.24501), "4.245010ms", "4ms 245us 10ns")
         test(Duration.milliseconds(1), "1ms")
 
         test(Duration.milliseconds(0.75), "750us")
-        test(Duration.microseconds(75.35), "75.350us")
-        test(Duration.microseconds(7.25), "7.250us")
+        test(Duration.microseconds(75.35), "75.35us")
+        test(Duration.microseconds(7.25), "7.25us")
         test(Duration.microseconds(1.035), "1.035us")
         test(Duration.microseconds(1.005), "1.005us")
-        test(Duration.nanoseconds(1800), "1.800us", "1800ns", "0.0000000005h")
+        test(Duration.nanoseconds(1800), "1.8us", "1800ns", "0.0000000005h")
 
         test(Duration.nanoseconds(950.5), "951ns")
         test(Duration.nanoseconds(85.23), "85ns")