diff --git a/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/LoggedData.kt b/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/LoggedData.kt
index a7cdbab02af..404f080bf52 100644
--- a/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/LoggedData.kt
+++ b/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/LoggedData.kt
@@ -98,9 +98,7 @@ internal abstract class LoggedData {
                 appendLine("- Exit code: ${exitCode.code} (${exitCode.name})")
                 appendDuration(duration)
                 appendLine()
-                appendLine("========== BEGIN: RAW COMPILER OUTPUT ==========")
-                if (compilerOutput.isNotEmpty()) appendLine(compilerOutput.trimEnd())
-                appendLine("========== END: RAW COMPILER OUTPUT ==========")
+                appendPotentiallyLargeOutput(compilerOutput, "RAW COMPILER OUTPUT", truncateLargeOutput = false)
                 appendLine()
                 appendLine(parameters)
             }
@@ -223,16 +221,24 @@ internal abstract class LoggedData {
             appendLine("- Exit code: ${runResult.exitCode ?: "<unknown>"}")
             appendDuration(runResult.duration)
             appendLine()
-            appendLine("========== BEGIN: STDOUT ==========")
-            val stdOut = runResult.processOutput.stdOut.filteredOutput
-            if (stdOut.isNotEmpty()) appendLine(stdOut.trimEnd())
-            appendLine("========== END: STDOUT ==========")
+            appendPotentiallyLargeOutput(runResult.processOutput.stdOut.filteredOutput, "STDOUT", truncateLargeOutput = true)
             appendLine()
-            appendLine("========== BEGIN: STDERR ==========")
-            val stdErr = runResult.processOutput.stdErr
-            if (stdErr.isNotEmpty()) appendLine(stdErr.trimEnd())
-            appendLine("========== END: STDERR ==========")
+            appendPotentiallyLargeOutput(runResult.processOutput.stdErr, "STDERR", truncateLargeOutput = true)
             return this
         }
+
+        private fun StringBuilder.appendPotentiallyLargeOutput(output: String, subject: String, truncateLargeOutput: Boolean) {
+            appendLine("========== BEGIN: $subject ==========")
+            if (output.length > MAX_PRINTED_OUTPUT_LENGTH && truncateLargeOutput) {
+                append(output.substring(0, MAX_PRINTED_OUTPUT_LENGTH).trimEnd()).appendLine("...")
+                appendLine()
+                appendLine("********** The output is too large (${output.length} characters in total), it has been truncated to avoid excessive logs **********")
+            } else if (output.isNotEmpty()) {
+                appendLine(output.trimEnd())
+            }
+            appendLine("========== END: $subject ==========")
+        }
+
+        private const val MAX_PRINTED_OUTPUT_LENGTH = 8 * 1024
     }
 }
diff --git a/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/runner/AbstractLocalProcessRunner.kt b/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/runner/AbstractLocalProcessRunner.kt
index 09da973bdfc..848426eabe5 100644
--- a/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/runner/AbstractLocalProcessRunner.kt
+++ b/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/runner/AbstractLocalProcessRunner.kt
@@ -75,7 +75,7 @@ internal abstract class AbstractLocalProcessRunner<R>(private val executionTimeo
 
     abstract inner class ResultHandler(runResult: RunResult.Completed) : AbstractRunner<R>.ResultHandler(runResult) {
         override fun handle(): R {
-            verifyExpectation(0, runResult.exitCode) { "$visibleProcessName exited with non-zero code." }
+            verifyExpectation(runResult.exitCode == 0) { "$visibleProcessName exited with non-zero code." }
 
             return doHandle()
         }
diff --git a/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/runner/AbstractRunner.kt b/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/runner/AbstractRunner.kt
index 52dfdc5bdd6..f424512d3e9 100644
--- a/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/runner/AbstractRunner.kt
+++ b/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/runner/AbstractRunner.kt
@@ -6,7 +6,6 @@
 package org.jetbrains.kotlin.konan.blackboxtest.support.runner
 
 import org.jetbrains.kotlin.konan.blackboxtest.support.LoggedData
-import org.jetbrains.kotlin.test.services.JUnit5Assertions.assertEquals
 import org.jetbrains.kotlin.test.services.JUnit5Assertions.assertTrue
 import org.jetbrains.kotlin.test.services.JUnit5Assertions.fail
 import org.opentest4j.TestAbortedException
@@ -47,10 +46,6 @@ internal abstract class AbstractRunner<R> {
         abstract fun getLoggedRun(): LoggedData
         abstract fun handle(): R
 
-        protected inline fun <T> verifyExpectation(expected: T, actual: T, crossinline errorMessage: () -> String) {
-            assertEquals(expected, actual) { getLoggedRun().withErrorMessage(errorMessage()) }
-        }
-
         protected inline fun verifyExpectation(shouldBeTrue: Boolean, crossinline errorMessage: () -> String) {
             assertTrue(shouldBeTrue) { getLoggedRun().withErrorMessage(errorMessage()) }
         }
diff --git a/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/runner/LocalTestRunner.kt b/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/runner/LocalTestRunner.kt
index 5400ddd815e..906a5c92abd 100644
--- a/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/runner/LocalTestRunner.kt
+++ b/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/runner/LocalTestRunner.kt
@@ -91,7 +91,9 @@ internal class LocalTestRunner(
 
         private fun verifyNonTestOutput(nonTestOutput: String) {
             testRun.runParameters.get<TestRunParameter.WithExpectedOutputData> {
-                verifyExpectation(convertLineSeparators(expectedOutputDataFile.readText()), convertLineSeparators(nonTestOutput)) {
+                // Don't use verifyExpectation(expected, actual) to avoid exposing potentially large test output in exception message
+                // and blowing up test logs.
+                verifyExpectation(convertLineSeparators(expectedOutputDataFile.readText()) == convertLineSeparators(nonTestOutput)) {
                     "Tested process output mismatch. See \"TEST STDOUT\" and \"EXPECTED OUTPUT DATA FILE\" below."
                 }
             }