diff --git a/engine/client/cl_qparse.c b/engine/client/cl_qparse.c
index f65522eb..0171da1d 100644
--- a/engine/client/cl_qparse.c
+++ b/engine/client/cl_qparse.c
@@ -844,7 +844,7 @@ static void CL_QuakeExecStuff( void )
 	while( 1 )
 	{
 		// skip whitespace up to a /n
-		while( *text && ((byte)*text) <= ' ' && *text != '\r' && *text != '\n' )
+		while( *text && ((byte)*text ) <= ' ' && *text != '\r' && *text != '\n' )
 			text++;
 
 		if( *text == '\n' || *text == '\r' )
diff --git a/engine/client/keys.c b/engine/client/keys.c
index 529e1e51..5064a0a6 100644
--- a/engine/client/keys.c
+++ b/engine/client/keys.c
@@ -553,7 +553,7 @@ static void Key_AddKeyCommands( int key, const char *kb, qboolean down )
 			}
 
 			buttonPtr = button;
-			while(( kb[i] <= ' ' || kb[i] == ';' ) && kb[i] != 0 )
+			while((((byte)kb[i]) <= ' ' || kb[i] == ';' ) && kb[i] != 0 )
 				i++;
 		}
 
diff --git a/engine/common/cmd.c b/engine/common/cmd.c
index 1e8837b3..3ba8dd1a 100644
--- a/engine/common/cmd.c
+++ b/engine/common/cmd.c
@@ -640,7 +640,7 @@ void Cmd_TokenizeString( const char *text )
 	while( 1 )
 	{
 		// skip whitespace up to a /n
-		while( *text && *text <= ' ' && *text != '\r' && *text != '\n' )
+		while( *text && ((byte)*text ) <= ' ' && *text != '\r' && *text != '\n' )
 			text++;
 
 		if( *text == '\n' || *text == '\r' )
diff --git a/engine/server/sv_game.c b/engine/server/sv_game.c
index b9dabf42..c5455429 100644
--- a/engine/server/sv_game.c
+++ b/engine/server/sv_game.c
@@ -256,7 +256,7 @@ void GAME_EXPORT SV_SetModel( edict_t *ent, const char *modelname )
 		return;
 	}
 
-	if( !modelname || modelname[0] <= ' ' )
+	if( !modelname || ((byte)modelname[0] ) <= ' ' )
 	{
 		Con_Printf( S_WARN "SV_SetModel: null name\n" );
 		return;