diff --git a/jam/jam.c b/jam/jam.c
index 4dfb4c4a9f..8958c2bbe8 100644
--- a/jam/jam.c
+++ b/jam/jam.c
@@ -168,7 +168,7 @@ extern char **environ;
 # endif
 # endif
 
-main( int argc, char **argv, char **arg_environ )
+int main( int argc, char **argv, char **arg_environ )
 {
 	int		n;
 	const char	*s;
diff --git a/jam/mkjambase.c b/jam/mkjambase.c
index 26224c977d..eebe3548ed 100644
--- a/jam/mkjambase.c
+++ b/jam/mkjambase.c
@@ -24,7 +24,7 @@
 # include <stdio.h>
 # include <string.h>
 
-main( int argc, char **argv, char **envp )
+int main( int argc, char **argv, char **envp )
 {
 	char buf[ 1024 ];
 	FILE *fin;