diff --git a/src/common/RewindManager.cxx b/src/common/RewindManager.cxx
index ab3f2cd6d..c162266db 100644
--- a/src/common/RewindManager.cxx
+++ b/src/common/RewindManager.cxx
@@ -185,11 +185,11 @@ string RewindManager::getMessage(RewindState& state)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 string RewindManager::getUnitString(Int64 cycles)
 {
-  const uInt64 scanlines = myOSystem.console().tia().scanlinesLastFrame();
+  const Int64 scanlines = myOSystem.console().tia().scanlinesLastFrame();
   const bool isNTSC = scanlines <= 285; // TODO: replace magic number
-  const uInt64 NTSC_FREQ = 1193182; // ~76*262*60
-  const uInt64 PAL_FREQ = 1182298; // ~76*312*50
-  const uInt64 freq = isNTSC ? NTSC_FREQ : PAL_FREQ; // = cycles/second
+  const Int64 NTSC_FREQ = 1193182; // ~76*262*60
+  const Int64 PAL_FREQ = 1182298; // ~76*312*50
+  const Int64 freq = isNTSC ? NTSC_FREQ : PAL_FREQ; // = cycles/second
 
   string unit;
   Int64 diffUnit;