diff --git a/Nasal/controls.nas b/Nasal/controls.nas
index 16d517a87..07a612bf3 100644
--- a/Nasal/controls.nas
+++ b/Nasal/controls.nas
@@ -470,3 +470,33 @@ _setlistener("/sim/signals/fdm-initialized", func {
     }
 });
 
+var replaySkip = func(skip_time)
+{
+    var t = getprop("/sim/replay/time");
+    if (t != "")
+    {
+        t+=skip_time;
+        if (t>getprop("/sim/replay/end-time"))
+            t = getprop("/sim/replay/end-time");
+        if (t<0)
+            t=0;
+        setprop("/sim/replay/time", t);
+    }
+}
+
+var speedup = func(speed_up)
+{
+    var t = getprop("/sim/speed-up");
+    if (speed_up < 0)
+    {
+        t = (t > 1/32) ? t/2 : 1/32;
+        if ((t<1)and(0==getprop("/sim/freeze/replay-state")))
+            t=1;
+    }
+    else
+    {
+        t = (t < 32) ? t*2 : 32;
+    }
+    setprop("/sim/speed-up", t);
+}
+
diff --git a/gui/dialogs/replay.xml b/gui/dialogs/replay.xml
index 6d192f821..acaef886c 100644
--- a/gui/dialogs/replay.xml
+++ b/gui/dialogs/replay.xml
@@ -183,17 +183,9 @@
 				<blue type="float">0.3</blue>
 				<alpha type="float">0.8</alpha>
 			</color>
-			<keynum>359</keynum>
 			<binding>
 			  <command>nasal</command>
-			  <script><![CDATA[
-				var t = getprop("/sim/speed-up");
-				if (t > 1/32)
-					t=t/2;
-				else
-					t=1/32;
-				setprop("/sim/speed-up", t);
-			  ]]></script>
+			  <script>controls.speedup(-1);</script>
 			</binding>
 		</button>
 		<text>
@@ -219,17 +211,9 @@
 				<blue type="float">0.3</blue>
 				<alpha type="float">0.8</alpha>
 			</color>
-			<keynum>357</keynum>
 			<binding>
 			  <command>nasal</command>
-			  <script><![CDATA[
-				var t = getprop("/sim/speed-up");
-				if (t < 32)
-					t=t*2;
-				else
-					t=32;
-				setprop("/sim/speed-up", t);
-			  ]]></script>
+			  <script>controls.speedup(1);</script>
 			</binding>
 		</button>
 
@@ -290,15 +274,7 @@
 			</color>
 			<binding>
 			  <command>nasal</command>
-			  <script><![CDATA[
-				var t = getprop("/sim/replay/time");
-				if (t != "")
-				{
-					t-=30;
-					if (t<0) t=0;
-					setprop("/sim/replay/time", t);
-				}
-			  ]]></script>
+			  <script>controls.replaySkip(-30);</script>
 			</binding>
 		</button>
 
@@ -312,18 +288,9 @@
 				<blue type="float">0.3</blue>
 				<alpha type="float">0.8</alpha>
 			</color>
-			<keynum>356</keynum>
 			<binding>
 			  <command>nasal</command>
-			  <script><![CDATA[
-				var t = getprop("/sim/replay/time");
-				if (t != "")
-				{
-					t-=5;
-					if (t<0) t=0;
-					setprop("/sim/replay/time", t);
-				}
-			  ]]></script>
+			  <script>controls.replaySkip(-5);</script>
 			</binding>
 		</button>
 
@@ -386,20 +353,9 @@
 				<blue type="float">0.3</blue>
 				<alpha type="float">0.8</alpha>
 			</color>
-			<keynum>358</keynum>
 			<binding>
 			  <command>nasal</command>
-			  <script><![CDATA[
-				var t = getprop("/sim/replay/time");
-				if (t != "")
-				{
-					t+=5;
-					if (t>getprop("/sim/replay/end-time"))
-						t = getprop("/sim/replay/end-time")-0.1;
-					if (t<0) t=0;
-					setprop("/sim/replay/time", t);
-				}
-			  ]]></script>
+			  <script>controls.replaySkip(5);</script>
 			</binding>
 		</button>
 
@@ -415,17 +371,7 @@
 			</color>
 			<binding>
 			  <command>nasal</command>
-			  <script><![CDATA[
-				var t = getprop("/sim/replay/time");
-				if (t != "")
-				{
-					t+=30;
-					if (t>getprop("/sim/replay/end-time"))
-						t = getprop("/sim/replay/end-time")-0.1;
-					if (t<0) t=0;
-					setprop("/sim/replay/time", t);
-				}
-			  ]]></script>
+			  <script>controls.replaySkip(30);</script>
 			</binding>
 		</button>
 	</group>
diff --git a/gui/dialogs/timeofday.xml b/gui/dialogs/timeofday.xml
index 1e9ae6b5a..07592a219 100644
--- a/gui/dialogs/timeofday.xml
+++ b/gui/dialogs/timeofday.xml
@@ -86,10 +86,8 @@
 				<button>
 					<legend>-</legend>
 					<binding>
-						<command>property-adjust</command>
-						<property>/sim/speed-up</property>
-						<min>1</min>
-						<step type="double">-1</step>
+						<command>nasal</command>
+						<script>controls.speedup(-1);</script>
 					</binding>
 				</button>
 				<button>
@@ -104,10 +102,8 @@
 				<button>
 					<legend>+</legend>
 					<binding>
-						<command>property-adjust</command>
-						<property>/sim/speed-up</property>
-						<min>1</min>
-						<step type="double">1</step>
+						<command>nasal</command>
+						<script>controls.speedup(1);</script>
 					</binding>
 				</button>
 			</group>
diff --git a/keyboard.xml b/keyboard.xml
index ce8a214ed..107e04889 100644
--- a/keyboard.xml
+++ b/keyboard.xml
@@ -1259,7 +1259,10 @@ top down before the key bindings are parsed.
   <binding>
    <command>nasal</command>
    <script>
-     controls.incAileron(-0.05, -1.0)
+     if (getprop("/sim/freeze/replay-state"))
+       controls.replaySkip(-5);
+     else
+       controls.incAileron(-0.05, -1.0)
    </script>
   </binding>
   <mod-shift>
@@ -1279,7 +1282,10 @@ top down before the key bindings are parsed.
   <binding>
    <command>nasal</command>
    <script>
-     controls.incElevator(0.05, -100)
+     if (getprop("/sim/freeze/replay-state"))
+       controls.speedup(1);
+     else
+       controls.incElevator(0.05, -100)
    </script>
   </binding>
   <mod-shift>
@@ -1299,7 +1305,10 @@ top down before the key bindings are parsed.
   <binding>
    <command>nasal</command>
    <script>
-     controls.incAileron(0.05, 1.0)
+     if (getprop("/sim/freeze/replay-state"))
+       controls.replaySkip(5);
+     else
+       controls.incAileron(0.05, 1.0)
    </script>
    <step type="double">0.05</step>
   </binding>
@@ -1320,7 +1329,10 @@ top down before the key bindings are parsed.
   <binding>
    <command>nasal</command>
    <script>
-     controls.incElevator(-0.05, 100)
+     if (getprop("/sim/freeze/replay-state"))
+       controls.speedup(-1);
+     else
+       controls.incElevator(-0.05, 100)
    </script>
   </binding>
   <mod-shift>
diff --git a/preferences.xml b/preferences.xml
index 7a708d2a7..d7081f3f3 100644
--- a/preferences.xml
+++ b/preferences.xml
@@ -740,6 +740,7 @@ Started September 2000 by David Megginson, david@megginson.com
 										userarchive="y">true</chat-display>
 			<chat-menu include="ATC/chat-menu-entries.xml"/>
 			<write-message-log type="bool">false</write-message-log>
+			<freeze-on-replay type="bool">true</freeze-on-replay>
 			<default-model type="string">Models/Geometry/glider.ac</default-model>
 		</multiplay>