diff --git a/2000/primenum/primenum.c b/2000/primenum/primenum.c
index ab228e996..a64a1c1b4 100644
--- a/2000/primenum/primenum.c
+++ b/2000/primenum/primenum.c
@@ -1,8 +1,8 @@
-#define BeginProgram void main(int argc, char *argv[])
+#define BeginProgram int main(int argc, char *argv[])
 #define CloseBrace }
 #define CommandLineArgument -1
 #define Declare int i,j,n,Flag=1;
-#define EndOfProgram return;
+#define EndOfProgram return 0;
 #define False 0;
 #define ForLoop ;for
 #define GetCommandLineArgument n=atoi(argv[1]);
diff --git a/thanks-for-fixes.md b/thanks-for-fixes.md
index b74ca8a4b..de4dc0211 100644
--- a/thanks-for-fixes.md
+++ b/thanks-for-fixes.md
@@ -1657,6 +1657,11 @@ itself a one-line like the code is in the original entry. Now it looks much more
 like the original entry but with the two fixes.
 
 
+## [2000/primenum](2000/primenum/primenum.c) ([README.md](2000/primenum/README.md]))
+
+Cody made this more portable by changing the `void main` to `int main`.
+
+
 ## [2000/thadgavin](2000/thadgavin/thadgavin.c) ([README.md](2000/thadgavin/README.md]))
 
 Cody fixed the code and added an appropriate make rule so that the SDL version