diff --git a/demux.cpp b/demux.cpp
index dea0d88..cf5c96f 100644
--- a/demux.cpp
+++ b/demux.cpp
@@ -58,7 +58,7 @@ int main(int argc, char *argv[])
                 exit(1);
             }
             if (w < n/nfds) {
-                fprintf(stderr, "short write: %d < %d\n", w, n/nfds);
+                fprintf(stderr, "short write: %d < %d\n", (int)w, (int)(n/nfds));
                 exit(1);
             }
         }
diff --git a/emailer.cpp b/emailer.cpp
index a4e6c42..43153f2 100644
--- a/emailer.cpp
+++ b/emailer.cpp
@@ -97,7 +97,7 @@ void email(const eas::Message &message, const char fn[])
         FILE *f = fdopen(pipeout[1], "w");
         if (f != NULL) {
             char boundary[80];
-            snprintf(boundary, sizeof(boundary), "%08x.%d", time(0), getpid());
+            snprintf(boundary, sizeof(boundary), "%08x.%d", (unsigned int)time(0), getpid());
             fprintf(f, "To: %s\n", From);
             fprintf(f, "From: %s\n", From);
             string name = fn;
diff --git a/splitter.cpp b/splitter.cpp
index 1e1c589..672b2e9 100644
--- a/splitter.cpp
+++ b/splitter.cpp
@@ -48,7 +48,7 @@ int main(int argc, char *argv[])
                 exit(1);
             }
             if (w < n) {
-                fprintf(stderr, "short write: %d < %d\n", w, n);
+                fprintf(stderr, "short write: %d < %d\n", (int)w, (int)n);
                 exit(1);
             }
         }