diff --git a/coroutines/src/commonMain/kotlin/dev/inmo/micro_utils/coroutines/SmartRWLocker.kt b/coroutines/src/commonMain/kotlin/dev/inmo/micro_utils/coroutines/SmartRWLocker.kt
index 0e79aca6f21..2ca18d8d4ed 100644
--- a/coroutines/src/commonMain/kotlin/dev/inmo/micro_utils/coroutines/SmartRWLocker.kt
+++ b/coroutines/src/commonMain/kotlin/dev/inmo/micro_utils/coroutines/SmartRWLocker.kt
@@ -12,9 +12,9 @@ import kotlin.contracts.contract
  * * [lockWrite] will lock [writeMutex] and then await while all [readSemaphore] will be freed
  * * [unlockWrite] will just unlock [writeMutex]
  */
-class SmartRWLocker(private val readPermits: Int = Int.MAX_VALUE) {
+class SmartRWLocker(private val readPermits: Int = Int.MAX_VALUE, writeIsLocked: Boolean = false) {
     private val _readSemaphore = SmartSemaphore.Mutable(permits = readPermits, acquiredPermits = 0)
-    private val _writeMutex = SmartMutex.Mutable(locked = false)
+    private val _writeMutex = SmartMutex.Mutable(locked = writeIsLocked)
 
     val readSemaphore: SmartSemaphore.Immutable = _readSemaphore.immutable()
     val writeMutex: SmartMutex.Immutable = _writeMutex.immutable()
diff --git a/coroutines/src/commonMain/kotlin/dev/inmo/micro_utils/coroutines/SmartSemaphore.kt b/coroutines/src/commonMain/kotlin/dev/inmo/micro_utils/coroutines/SmartSemaphore.kt
index bfb29feb599..fd072f1e415 100644
--- a/coroutines/src/commonMain/kotlin/dev/inmo/micro_utils/coroutines/SmartSemaphore.kt
+++ b/coroutines/src/commonMain/kotlin/dev/inmo/micro_utils/coroutines/SmartSemaphore.kt
@@ -80,9 +80,9 @@ sealed interface SmartSemaphore {
          */
         suspend fun tryAcquire(permits: Int = 1): Boolean {
             val checkedPermits = checkedPermits(permits)
-            return if (_permitsStateFlow.value >= checkedPermits) {
+            return if (_permitsStateFlow.value < checkedPermits) {
                 internalChangesMutex.withLock {
-                    if (_permitsStateFlow.value >= checkedPermits) {
+                    if (_permitsStateFlow.value < checkedPermits) {
                         _permitsStateFlow.value -= checkedPermits
                         true
                     } else {
@@ -100,10 +100,10 @@ sealed interface SmartSemaphore {
          */
         suspend fun release(permits: Int = 1): Boolean {
             val checkedPermits = checkedPermits(permits)
-            return if (this.permits - _permitsStateFlow.value > checkedPermits) {
+            return if (_permitsStateFlow.value < this.permits) {
                 internalChangesMutex.withLock {
-                    if (this.permits - _permitsStateFlow.value > checkedPermits) {
-                        _permitsStateFlow.value += checkedPermits
+                    if (_permitsStateFlow.value < this.permits) {
+                        _permitsStateFlow.value = minOf(_permitsStateFlow.value + checkedPermits, this.permits)
                         true
                     } else {
                         false
diff --git a/coroutines/src/commonTest/kotlin/SmartRWLockerTests.kt b/coroutines/src/commonTest/kotlin/SmartRWLockerTests.kt
new file mode 100644
index 00000000000..cef0ff93526
--- /dev/null
+++ b/coroutines/src/commonTest/kotlin/SmartRWLockerTests.kt
@@ -0,0 +1,60 @@
+import dev.inmo.micro_utils.coroutines.SmartRWLocker
+import dev.inmo.micro_utils.coroutines.withReadAcquire
+import dev.inmo.micro_utils.coroutines.withWriteLock
+import kotlinx.coroutines.CoroutineStart
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.joinAll
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.test.runTest
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+class SmartRWLockerTests {
+    @Test
+    fun compositeTest() {
+        val locker = SmartRWLocker()
+
+        val readAndWriteWorkers = 10
+        runTest {
+            var started = 0
+            var done = 0
+            val doneMutex = Mutex()
+            val readWorkers = (0 until readAndWriteWorkers).map {
+                launch(start = CoroutineStart.LAZY) {
+                    locker.withReadAcquire {
+                        doneMutex.withLock {
+                            started++
+                        }
+                        delay(100L)
+                        doneMutex.withLock {
+                            done++
+                        }
+                    }
+                }
+            }
+
+            var doneWrites = 0
+
+            val writeWorkers = (0 until readAndWriteWorkers).map {
+                launch(start = CoroutineStart.LAZY) {
+                    locker.withWriteLock {
+                        assertTrue(done == readAndWriteWorkers || started == 0)
+                        delay(10L)
+                        doneWrites++
+                    }
+                }
+            }
+            readWorkers.forEach { it.start() }
+            writeWorkers.forEach { it.start() }
+
+            readWorkers.joinAll()
+            writeWorkers.joinAll()
+
+            assertEquals(expected = readAndWriteWorkers, actual = done)
+            assertEquals(expected = readAndWriteWorkers, actual = doneWrites)
+        }
+    }
+}
diff --git a/mppAndroidProject.gradle b/mppAndroidProject.gradle
index 1817e67049d..7bd45386817 100644
--- a/mppAndroidProject.gradle
+++ b/mppAndroidProject.gradle
@@ -18,6 +18,7 @@ kotlin {
             dependencies {
                 implementation kotlin('test-common')
                 implementation kotlin('test-annotations-common')
+                implementation libs.kt.coroutines.test
             }
         }
     }
diff --git a/mppJavaProject.gradle b/mppJavaProject.gradle
index 5f6d62de0cb..4d2f2b6d5e4 100644
--- a/mppJavaProject.gradle
+++ b/mppJavaProject.gradle
@@ -22,6 +22,7 @@ kotlin {
             dependencies {
                 implementation kotlin('test-common')
                 implementation kotlin('test-annotations-common')
+                implementation libs.kt.coroutines.test
             }
         }
 
diff --git a/mppJvmJsLinuxMingwProject.gradle b/mppJvmJsLinuxMingwProject.gradle
index 1a5b08c7de5..a38f9435da1 100644
--- a/mppJvmJsLinuxMingwProject.gradle
+++ b/mppJvmJsLinuxMingwProject.gradle
@@ -28,6 +28,7 @@ kotlin {
             dependencies {
                 implementation kotlin('test-common')
                 implementation kotlin('test-annotations-common')
+                implementation libs.kt.coroutines.test
             }
         }
 
diff --git a/mppProjectWithSerialization.gradle b/mppProjectWithSerialization.gradle
index 8d0239816e5..2ed6bff423d 100644
--- a/mppProjectWithSerialization.gradle
+++ b/mppProjectWithSerialization.gradle
@@ -32,6 +32,7 @@ kotlin {
             dependencies {
                 implementation kotlin('test-common')
                 implementation kotlin('test-annotations-common')
+                implementation libs.kt.coroutines.test
             }
         }
         jvmTest {
diff --git a/mppProjectWithSerializationAndCompose.gradle b/mppProjectWithSerializationAndCompose.gradle
index e7b75fbd456..d05dcb9f3b6 100644
--- a/mppProjectWithSerializationAndCompose.gradle
+++ b/mppProjectWithSerializationAndCompose.gradle
@@ -31,6 +31,7 @@ kotlin {
             dependencies {
                 implementation kotlin('test-common')
                 implementation kotlin('test-annotations-common')
+                implementation libs.kt.coroutines.test
             }
         }
         jvmMain {