diff --git a/mi/mipointer.c b/mi/mipointer.c
index acfcb1bd6..be1895654 100644
--- a/mi/mipointer.c
+++ b/mi/mipointer.c
@@ -437,7 +437,7 @@ miPointerSetScreen(DeviceIntPtr pDev, int screen_no, int x, int y)
 }
 
 ScreenPtr
-miPointerCurrentScreen ()
+miPointerCurrentScreen (void)
 {
     return miPointerGetScreen(inputInfo.pointer);
 }
diff --git a/mi/miscrinit.c b/mi/miscrinit.c
index 92b3981aa..157a17fa3 100644
--- a/mi/miscrinit.c
+++ b/mi/miscrinit.c
@@ -297,7 +297,7 @@ static int privateKeyIndex;
 static DevPrivateKey privateKey = &privateKeyIndex;
 
 DevPrivateKey
-miAllocateGCPrivateIndex()
+miAllocateGCPrivateIndex(void)
 {
     return privateKey;
 }
diff --git a/mi/mispans.c b/mi/mispans.c
index e59d711ae..33882a9e1 100644
--- a/mi/mispans.c
+++ b/mi/mispans.c
@@ -65,8 +65,7 @@ Written by Joel McCormack, Summer 1989.
 */
 
 
-void miInitSpanGroup(spanGroup)
-    SpanGroup *spanGroup;
+void miInitSpanGroup(SpanGroup *spanGroup)
 {
     spanGroup->size = 0;
     spanGroup->count = 0;