diff --git a/app/src/gambas3-selftest/.project b/app/src/gambas3-selftest/.project
index f2f00a9f9..4f2231491 100644
--- a/app/src/gambas3-selftest/.project
+++ b/app/src/gambas3-selftest/.project
@@ -2,7 +2,7 @@
 Title=Gambas3 Selftest
 Startup=mTest
 Icon=.hidden/logo.png
-Version=3.17.90
+Version=3.18.90
 VersionFile=1
 Component=gb.image
 Component=gb.gui
diff --git a/app/src/gambas3-selftest/.src/TestSources/mTest.module b/app/src/gambas3-selftest/.src/TestSources/mTest.module
index c6db32339..b46b1d532 100644
--- a/app/src/gambas3-selftest/.src/TestSources/mTest.module
+++ b/app/src/gambas3-selftest/.src/TestSources/mTest.module
@@ -4,83 +4,16 @@ Export
 
 Fast
 
-Private fTime As Float = Timer
-
-Library "libc:6"
-Private Extern modf(param As Float, pp As Pointer) As Float
-
-#If SYSTEM = "Linux"
-Private sSystem As String = "Linux"
-#Else If SYSTEM = "FreeBSD"
-Private sSystem As String = "FreeBSD"
-#Else If SYSTEM = "OpenBSD"
-Private sSystem As String = "OpenBSD"
-#Else If SYSTEM = "NetBSD"
-Private sSystem As String = "NetBSD"
-#Else If SYSTEM = "Solaris"
-Private sSystem As String = "Solaris"
-#Else
-Private sSystem As String = "Unknown"
-#Endif
-
-#If ARCHITECTURE = "x86"
-Private sArchitecture As String = "x86"
-#Else If ARCHITECTURE = "x86_64"
-Private sArchitecture As String = "x86_64"
-#Else If ARCHITECTURE = "ARM"
-Private sArchitecture As String = "ARM"
-#Else If ARCHITECTURE = "PPC"
-Private sArchitecture As String = "PPC"
-#Else
-Private sArchitecture As String = "Unknown"
-#Endif
-
-#If Debug
-Private DebuggingEnabled As Boolean = True
-#Else
-Private DebuggingEnabled As Boolean = False
-#Endif
-
 Private $sGrep As String
 Private sSearch As New String[]
-Private Const TestConst2 As Integer = 2
-Public Const LowestLong As Long = -9223372036854775808
-Public Const HighestLong As Long = 9223372036854775807
-Public Const LowestInteger As Integer = -2147483648
-Public Const HighestInteger As Integer = 2147483647
-Public Const LowestShort As Short = -32768
-Public Const HighestShort As Short = 32767
-
-Public Struct MyPoint
-    x As Integer
-    y As Integer
-End Struct
 
 Private arr As New Integer[2, 2]
-
-Private hProcess As Process
-Private sTest As String '
-
-Private hStillHere1 As New MyPoint
-
-Private Enum Zero, One, Two
-
 Public hFormForEvent As New TestClass3
 
 Private iTestAndIf As Integer = 0
-
-Private Errors As New String[]
-
-Private hFile2 As File
 Private iseek As Integer
 
 Private hCrash2 As New ChildClass
-
-Private bRun As Boolean = False
-
-Public Const kkX As Integer = 1999
-Public Const kkY As Integer = 1499
-
 Public hChild As New ChildClass
 
 Public timo As Integer
@@ -90,9 +23,6 @@ Public Const gHour As Integer = 30833
 
 Public Const bbb As Integer = 50
 Public bArray As New Boolean[100]
-Private ctrl_dc[7] As Integer
-
-Public sPublic As String = "Test"
 
 Fast Private Sub VoidFn()
 
diff --git a/app/src/gambas3-selftest/.src/Tests/GambasSelftests.test b/app/src/gambas3-selftest/.src/Tests/GambasSelftests.test
index 76683cab9..3c59e8910 100644
--- a/app/src/gambas3-selftest/.src/Tests/GambasSelftests.test
+++ b/app/src/gambas3-selftest/.src/Tests/GambasSelftests.test
@@ -1,11 +1,7 @@
 ' Gambas test file
 
-'Export
-
 Fast
 
-'Private fTime As Float = Timer
-
 Library "libc:6"
 Private Extern modf(param As Float, pp As Pointer) As Float
 
@@ -722,12 +718,6 @@ Fast Public Function FastTests() As Integer
         Assert.Fail("CShort")
     Endif
 
-    Test.Note("CShort Overflow")
-    Test.TODO("Expected error, that an overflow happened in CShort")
-    Dim siShort As Short
-    Try siShort = CShort(100000)
-    Assert.Error()
-
     Test.Note("CSingle")
     If Format$(CSingle("+3.1416"), "#.####") <> Str$(3.1416) Or CSingle("1.0E+3") <> 1000 Then
         '' Or CSng(Pi) <> 3.141592741013 Then' Actually gives 3.14159274101257  Which is correct?
@@ -2314,3 +2304,35 @@ Fast Public Function _TestAndIf() As Integer
     Return 0
 
 End
+
+Fast Public Sub IntegerOverflows()
+
+    Dim s As Short
+    Dim i As Integer
+    Dim l As Integer
+
+    Test.Note("Short Overflow")
+    Try s = HighestShort + 1
+    Assert.Error("Short overflow error")
+
+    Test.Note("Integer Overflow")
+    Try i = HighestInteger + 1
+    Assert.Error("Int overflow error")
+
+    Test.Note("Long Overflow")
+    Try l = HighestLong + 1
+    Assert.Error("Long overflow error")
+
+    Test.Note("Short Underflow")
+    Try s = LowestShort - 1
+    Assert.Error("Short underflow error")
+
+    Test.Note("Integer Underflow")
+    Try i = LowestInteger - 1
+    Assert.Error("Int underflow error")
+
+    Test.Note("Long Underflow")
+    Try l = LowestLong - 1
+    Assert.Error("Long underflow error")
+
+End
diff --git a/app/src/gambas3-selftest/.test b/app/src/gambas3-selftest/.test
index 431eb86ca..38b980b88 100644
--- a/app/src/gambas3-selftest/.test
+++ b/app/src/gambas3-selftest/.test
@@ -1,15 +1,15 @@
 [TestSuites]
 Count=4
 TestWith=1
-Default="Errorhandling.GeneralError"
+Default="GambasSelftests.IntegerOverflows"
 
 [TestSuites/1]
 Name="Fast"
-Tests="Errorhandling.GeneralError,GambasSelftests.FastTests;TCatch;TError;TVal,LocalStaticFun.CountALot;Saysth;SwingDoor"
+Tests="Errorhandling.GeneralError,GambasSelftests.FastTests;IntegerOverflows;TCatch;TError;TVal,LocalStaticFun.CountALot;Saysth;SwingDoor"
 
 [TestSuites/2]
 Name="Full"
-Tests="Errorhandling.GeneralError,FileReadWrite.FileReadWrite;ReadUrandom;ReadZero,GambasSelftests.FastTests;TCatch;TError;TVal,LocalStaticFun.CountALot;Saysth;SwingDoor,SlowThousandsProcs.FewThousandProcesses,Timers.Timers"
+Tests="Errorhandling.GeneralError,FileReadWrite.FileReadWrite;ReadUrandom;ReadZero,GambasSelftests.FastTests;IntegerOverflows;TCatch;TError;TVal,LocalStaticFun.CountALot;Saysth;SwingDoor,SlowThousandsProcs.FewThousandProcesses,Timers.Timers"
 
 [TestSuites/3]
 Name="Slow tests"
@@ -17,5 +17,5 @@ Tests="FileReadWrite.FileReadWrite;ReadUrandom;ReadZero,SlowThousandsProcs.FewTh
 
 [TestSuites/4]
 Name="Production"
-Tests="Errorhandling.GeneralError,FileReadWrite.FileReadWrite;ReadUrandom;ReadZero,GambasSelftests.FastTests;TCatch;TError;TVal,LocalStaticFun.CountALot;Saysth;SwingDoor,SlowThousandsProcs.FewThousandProcesses"
+Tests="Errorhandling.GeneralError,FileReadWrite.FileReadWrite;ReadUrandom;ReadZero,GambasSelftests.FastTests;IntegerOverflows;TCatch;TError;TVal,LocalStaticFun.CountALot;Saysth;SwingDoor,SlowThousandsProcs.FewThousandProcesses"
 
diff --git a/app/src/gambas3-selftest/run.sh b/app/src/gambas3-selftest/run.sh
index 9ba102cb4..166afb680 100755
--- a/app/src/gambas3-selftest/run.sh
+++ b/app/src/gambas3-selftest/run.sh
@@ -10,6 +10,9 @@ fi
 MYDIR=$(cd `dirname $0` && pwd)
 
 # run Production without JIT
+
+echo "########### Run without JIT ############"
+
 gbx3 -j -T "$TESTSUITE" $MYDIR
 
 if [ $? -ne 0 ] 
@@ -19,7 +22,8 @@ then
 fi
 
 # run Production with JIT
-GB_NO_JIT=01 GB_JIT_CFLAGS=-O0 gbx3 -T "$TESTSUITE" $MYDIR
+echo "########### Now run with JIT ############"
+GB_JIT_CFLAGS=-O0 gbx3 -T "$TESTSUITE" $MYDIR
 
 if [ $? -ne 0 ] 
 then
diff --git a/main/lib/test/gb.test/.test b/main/lib/test/gb.test/.test
index 98206ab20..d5e7fd01c 100644
--- a/main/lib/test/gb.test/.test
+++ b/main/lib/test/gb.test/.test
@@ -1,6 +1,6 @@
 [TestSuites]
 Count=8
-TestWith=4
+TestWith=6
 Default="TCrashes.DoACrash"
 
 [TestSuites/1]