diff --git a/randr/randr.c b/randr/randr.c
index 078514a3c..59d101ba7 100644
--- a/randr/randr.c
+++ b/randr/randr.c
@@ -50,6 +50,7 @@ static int RRNScreens;
     real->mem = priv->mem; \
 }
 
+static int ProcRRDispatch(ClientPtr pClient);
 static int SProcRRDispatch(ClientPtr pClient);
 
 int RREventBase;
@@ -737,6 +738,16 @@ RRVerticalRefresh(xRRModeInfo * mode)
     return (CARD16) refresh;
 }
 
+static int
+ProcRRDispatch(ClientPtr client)
+{
+    REQUEST(xReq);
+    if (stuff->data >= RRNumberRequests || !ProcRandrVector[stuff->data])
+        return BadRequest;
+    UpdateCurrentTimeIf();
+    return (*ProcRandrVector[stuff->data]) (client);
+}
+
 static int _X_COLD
 SProcRRDispatch(ClientPtr client)
 {
diff --git a/randr/randrstr_priv.h b/randr/randrstr_priv.h
index a125f293a..7f802215f 100644
--- a/randr/randrstr_priv.h
+++ b/randr/randrstr_priv.h
@@ -33,6 +33,7 @@
 
 extern int RREventBase, RRErrorBase;
 
+extern int (*ProcRandrVector[RRNumberRequests]) (ClientPtr);
 extern int (*SProcRandrVector[RRNumberRequests]) (ClientPtr);
 
 extern RESTYPE RRClientType, RREventType;     /* resource types for event masks */
@@ -139,6 +140,4 @@ int ProcRRQueryVersion(ClientPtr client);
 
 int ProcRRSelectInput(ClientPtr client);
 
-int ProcRRDispatch(ClientPtr client);
-
 #endif /* _XSERVER_RANDRSTR_PRIV_H_ */
diff --git a/randr/rrdispatch.c b/randr/rrdispatch.c
index 866c6f252..4381f52ca 100644
--- a/randr/rrdispatch.c
+++ b/randr/rrdispatch.c
@@ -211,69 +211,60 @@ ProcRRSelectInput(ClientPtr client)
     return Success;
 }
 
-int
-ProcRRDispatch(ClientPtr client)
-{
-    REQUEST(xReq);
-    UpdateCurrentTimeIf();
-
-    switch (stuff->data) {
-        case X_RRQueryVersion:              return ProcRRQueryVersion(client);
-        case X_RRSetScreenConfig:           return ProcRRSetScreenConfig(client);
-        case X_RRSelectInput:               return ProcRRSelectInput(client);
-        case X_RRGetScreenInfo:             return ProcRRGetScreenInfo(client);
-
-        /* V1.2 additions */
-        case X_RRGetScreenSizeRange:        return ProcRRGetScreenSizeRange(client);
-        case X_RRSetScreenSize:             return ProcRRSetScreenSize(client);
-        case X_RRGetScreenResources:        return ProcRRGetScreenResources(client);
-        case X_RRGetOutputInfo:             return ProcRRGetOutputInfo(client);
-        case X_RRListOutputProperties:      return ProcRRListOutputProperties(client);
-        case X_RRQueryOutputProperty:       return ProcRRQueryOutputProperty(client);
-        case X_RRConfigureOutputProperty:   return ProcRRConfigureOutputProperty(client);
-        case X_RRChangeOutputProperty:      return ProcRRChangeOutputProperty(client);
-        case X_RRDeleteOutputProperty:      return ProcRRDeleteOutputProperty(client);
-        case X_RRGetOutputProperty:         return ProcRRGetOutputProperty(client);
-        case X_RRCreateMode:                return ProcRRCreateMode(client);
-        case X_RRDestroyMode:               return ProcRRDestroyMode(client);
-        case X_RRAddOutputMode:             return ProcRRAddOutputMode(client);
-        case X_RRDeleteOutputMode:          return ProcRRDeleteOutputMode(client);
-        case X_RRGetCrtcInfo:               return ProcRRGetCrtcInfo(client);
-        case X_RRSetCrtcConfig:             return ProcRRSetCrtcConfig(client);
-        case X_RRGetCrtcGammaSize:          return ProcRRGetCrtcGammaSize(client);
-        case X_RRGetCrtcGamma:              return ProcRRGetCrtcGamma(client);
-        case X_RRSetCrtcGamma:              return ProcRRSetCrtcGamma(client);
-
-        /* V1.3 additions */
-        case X_RRGetScreenResourcesCurrent: return ProcRRGetScreenResourcesCurrent(client);
-        case X_RRSetCrtcTransform:          return ProcRRSetCrtcTransform(client);
-        case X_RRGetCrtcTransform:          return ProcRRGetCrtcTransform(client);
-        case X_RRGetPanning:                return ProcRRGetPanning(client);
-        case X_RRSetPanning:                return ProcRRSetPanning(client);
-        case X_RRSetOutputPrimary:          return ProcRRSetOutputPrimary(client);
-        case X_RRGetOutputPrimary:          return ProcRRGetOutputPrimary(client);
-
-        /* V1.4 additions */
-        case X_RRGetProviders:              return ProcRRGetProviders(client);
-        case X_RRGetProviderInfo:           return ProcRRGetProviderInfo(client);
-        case X_RRSetProviderOffloadSink:    return ProcRRSetProviderOffloadSink(client);
-        case X_RRSetProviderOutputSource:   return ProcRRSetProviderOutputSource(client);
-        case X_RRListProviderProperties:    return ProcRRListProviderProperties(client);
-        case X_RRQueryProviderProperty:     return ProcRRQueryProviderProperty(client);
-        case X_RRConfigureProviderProperty: return ProcRRConfigureProviderProperty(client);
-        case X_RRChangeProviderProperty:    return ProcRRChangeProviderProperty(client);
-        case X_RRDeleteProviderProperty:    return ProcRRDeleteProviderProperty(client);
-        case X_RRGetProviderProperty:       return ProcRRGetProviderProperty(client);
-
-        /* V1.5 additions */
-        case X_RRGetMonitors:               return ProcRRGetMonitors(client);
-        case X_RRSetMonitor:                return ProcRRSetMonitor(client);
-        case X_RRDeleteMonitor:             return ProcRRDeleteMonitor(client);
-
-        /* V1.6 additions */
-        case X_RRCreateLease:               return ProcRRCreateLease(client);
-        case X_RRFreeLease:                 return ProcRRFreeLease(client);
-    }
-
-    return BadRequest;
-}
+int (*ProcRandrVector[RRNumberRequests]) (ClientPtr) = {
+    ProcRRQueryVersion,         /* 0 */
+/* we skip 1 to make old clients fail pretty immediately */
+        NULL,                   /* 1 ProcRandrOldGetScreenInfo */
+/* V1.0 apps share the same set screen config request id */
+        ProcRRSetScreenConfig,  /* 2 */
+        NULL,                   /* 3 ProcRandrOldScreenChangeSelectInput */
+/* 3 used to be ScreenChangeSelectInput; deprecated */
+        ProcRRSelectInput,      /* 4 */
+        ProcRRGetScreenInfo,    /* 5 */
+/* V1.2 additions */
+        ProcRRGetScreenSizeRange,       /* 6 */
+        ProcRRSetScreenSize,    /* 7 */
+        ProcRRGetScreenResources,       /* 8 */
+        ProcRRGetOutputInfo,    /* 9 */
+        ProcRRListOutputProperties,     /* 10 */
+        ProcRRQueryOutputProperty,      /* 11 */
+        ProcRRConfigureOutputProperty,  /* 12 */
+        ProcRRChangeOutputProperty,     /* 13 */
+        ProcRRDeleteOutputProperty,     /* 14 */
+        ProcRRGetOutputProperty,        /* 15 */
+        ProcRRCreateMode,       /* 16 */
+        ProcRRDestroyMode,      /* 17 */
+        ProcRRAddOutputMode,    /* 18 */
+        ProcRRDeleteOutputMode, /* 19 */
+        ProcRRGetCrtcInfo,      /* 20 */
+        ProcRRSetCrtcConfig,    /* 21 */
+        ProcRRGetCrtcGammaSize, /* 22 */
+        ProcRRGetCrtcGamma,     /* 23 */
+        ProcRRSetCrtcGamma,     /* 24 */
+/* V1.3 additions */
+        ProcRRGetScreenResourcesCurrent,        /* 25 */
+        ProcRRSetCrtcTransform, /* 26 */
+        ProcRRGetCrtcTransform, /* 27 */
+        ProcRRGetPanning,       /* 28 */
+        ProcRRSetPanning,       /* 29 */
+        ProcRRSetOutputPrimary, /* 30 */
+        ProcRRGetOutputPrimary, /* 31 */
+/* V1.4 additions */
+        ProcRRGetProviders,     /* 32 */
+        ProcRRGetProviderInfo,  /* 33 */
+        ProcRRSetProviderOffloadSink, /* 34 */
+        ProcRRSetProviderOutputSource, /* 35 */
+        ProcRRListProviderProperties,    /* 36 */
+        ProcRRQueryProviderProperty,     /* 37 */
+        ProcRRConfigureProviderProperty, /* 38 */
+        ProcRRChangeProviderProperty, /* 39 */
+        ProcRRDeleteProviderProperty, /* 40 */
+        ProcRRGetProviderProperty,    /* 41 */
+/* V1.5 additions */
+        ProcRRGetMonitors,            /* 42 */
+        ProcRRSetMonitor,             /* 43 */
+        ProcRRDeleteMonitor,          /* 44 */
+/* V1.6 additions */
+        ProcRRCreateLease,            /* 45 */
+        ProcRRFreeLease,              /* 46 */
+};