diff --git a/errorStuff.h b/errorStuff.h
index 8605c5f..5b94cbe 100644
--- a/errorStuff.h
+++ b/errorStuff.h
@@ -3,6 +3,8 @@
 
 #include "macrossTypes.h"
 
+#include <stdarg.h>
+
 void puntOnError(errorType theError, ...);
 void printErrorMessage(errorType theError, va_list ap);
 void error(errorType theError, ...);
diff --git a/listing.h b/listing.h
index 2512d4a..181e5de 100644
--- a/listing.h
+++ b/listing.h
@@ -3,6 +3,8 @@
 
 #include "macrossTypes.h"
 
+#include <stdarg.h>
+
 void outputListing(void);
 void terminateListingFiles(void);
 void generateListing(void);
diff --git a/main.c b/main.c
index 7226ecb..f050847 100644
--- a/main.c
+++ b/main.c
@@ -48,9 +48,14 @@ main(int argc, char **argv)
 	initializeStuff(argc, argv);
 	yyparse();
 	finishUp();
+	/* sbrk() ends up having different signatures depending on compiler
+         * flags and system. We cast here out of an abundance of caution.
+         * This, and the "end" variable above, are both just for this one
+         * diagnostic, so if they're causing your build trouble, they can
+         * be safely deleted. --mcm */
 	if (emitPrint)
-		printf("storage high water mark 0x%x == %d\n", sbrk(0) - (void *)(&end),
-			sbrk(0) - (void *)(&end));
+		printf("storage high water mark 0x%x == %d\n", (void *)sbrk(0) - (void *)(&end),
+			(void *)sbrk(0) - (void *)(&end));
 	if (errorFlag)
 		chokePukeAndDie();
 	return 0;