diff --git a/codeCore/src/prog8/code/target/Mflpt5.kt b/codeCore/src/prog8/code/target/Mflpt5.kt
index abb1e4f0d..ade58279b 100644
--- a/codeCore/src/prog8/code/target/Mflpt5.kt
+++ b/codeCore/src/prog8/code/target/Mflpt5.kt
@@ -19,7 +19,7 @@ data class Mflpt5(val b0: UByte, val b1: UByte, val b2: UByte, val b3: UByte, va
 
             val flt = num.toDouble()
             if (flt !in FLOAT_MAX_NEGATIVE..FLOAT_MAX_POSITIVE)
-                throw InternalCompilerException("floating point number out of 5-byte mflpt range: $this")
+                throw InternalCompilerException("floating point number out of 5-byte mflpt range: $flt")
             if (flt == 0.0)
                 return zero
 
@@ -40,7 +40,7 @@ data class Mflpt5(val b0: UByte, val b1: UByte, val b2: UByte, val b3: UByte, va
 
             return when {
                 exponent < 0 -> zero  // underflow, use zero instead
-                exponent > 255 -> throw InternalCompilerException("floating point overflow: $this")
+                exponent > 255 -> throw InternalCompilerException("floating point overflow: $flt")
                 exponent == 0 -> zero
                 else -> {
                     val mantLong = mantissa.toLong()
diff --git a/compiler/test/TestNumbers.kt b/compiler/test/TestNumbers.kt
index 4c0005097..71245e338 100644
--- a/compiler/test/TestNumbers.kt
+++ b/compiler/test/TestNumbers.kt
@@ -85,10 +85,10 @@ class TestNumbers: FunSpec({
         Mflpt5.fromNumber(1.7e-39) shouldBe Mflpt5(0x00u, 0x00u, 0x00u, 0x00u, 0x00u)
         Mflpt5.fromNumber(-1.7e-38) shouldBe Mflpt5(0x03u, 0xb9u, 0x1du, 0x15u, 0x63u)
         Mflpt5.fromNumber(-1.7e-39) shouldBe Mflpt5(0x00u, 0x00u, 0x00u, 0x00u, 0x00u)
-        shouldThrow<InternalCompilerException> { Mflpt5.fromNumber(1.7014118346e+38) }
-        shouldThrow<InternalCompilerException> { Mflpt5.fromNumber(-1.7014118346e+38) }
-        shouldThrow<InternalCompilerException> { Mflpt5.fromNumber(1.7014118347e+38) }
-        shouldThrow<InternalCompilerException> { Mflpt5.fromNumber(-1.7014118347e+38) }
+        shouldThrow<InternalCompilerException> { Mflpt5.fromNumber(1.7014118346e+38) }.message shouldContain  "mflpt range: 1.7014118346E38"
+        shouldThrow<InternalCompilerException> { Mflpt5.fromNumber(-1.7014118346e+38) }.message shouldContain "mflpt range: -1.7014118346E38"
+        shouldThrow<InternalCompilerException> { Mflpt5.fromNumber(1.7014118347e+38) }.message shouldContain "mflpt range: 1.7014118347E38"
+        shouldThrow<InternalCompilerException> { Mflpt5.fromNumber(-1.7014118347e+38) }.message shouldContain "mflpt range: -1.7014118347E38"
     }
 
     test("testMflpt5ToFloat") {