diff --git a/updater/install.c b/updater/install.c
index 1fc4fd3..9fa06a2 100644
--- a/updater/install.c
+++ b/updater/install.c
@@ -97,13 +97,13 @@
         const MtdPartition* mtd;
         mtd = mtd_find_partition_by_name(location);
         if (mtd == NULL) {
-            fprintf(stderr, "%s: no mtd partition named \"%s\"",
+            printf("%s: no mtd partition named \"%s\"",
                     name, location);
             result = strdup("");
             goto done;
         }
         if (mtd_mount_partition(mtd, mount_point, fs_type, 0 /* rw */) != 0) {
-            fprintf(stderr, "mtd mount of %s failed: %s\n",
+            printf("mtd mount of %s failed: %s\n",
                     location, strerror(errno));
             result = strdup("");
             goto done;
@@ -112,7 +112,7 @@
     } else {
         if (mount(location, mount_point, fs_type,
                   MS_NOATIME | MS_NODEV | MS_NODIRATIME, "") < 0) {
-            fprintf(stderr, "%s: failed to mount %s at %s: %s\n",
+            printf("%s: failed to mount %s at %s: %s\n",
                     name, location, mount_point, strerror(errno));
             result = strdup("");
         } else {
@@ -175,7 +175,7 @@
     scan_mounted_volumes();
     const MountedVolume* vol = find_mounted_volume_by_mount_point(mount_point);
     if (vol == NULL) {
-        fprintf(stderr, "unmount of %s failed; no such volume\n", mount_point);
+        printf("unmount of %s failed; no such volume\n", mount_point);
         result = strdup("");
     } else {
         unmount_mounted_volume(vol);
@@ -233,25 +233,25 @@
         mtd_scan_partitions();
         const MtdPartition* mtd = mtd_find_partition_by_name(location);
         if (mtd == NULL) {
-            fprintf(stderr, "%s: no mtd partition named \"%s\"",
+            printf("%s: no mtd partition named \"%s\"",
                     name, location);
             result = strdup("");
             goto done;
         }
         MtdWriteContext* ctx = mtd_write_partition(mtd);
         if (ctx == NULL) {
-            fprintf(stderr, "%s: can't write \"%s\"", name, location);
+            printf("%s: can't write \"%s\"", name, location);
             result = strdup("");
             goto done;
         }
         if (mtd_erase_blocks(ctx, -1) == -1) {
             mtd_write_close(ctx);
-            fprintf(stderr, "%s: failed to erase \"%s\"", name, location);
+            printf("%s: failed to erase \"%s\"", name, location);
             result = strdup("");
             goto done;
         }
         if (mtd_write_close(ctx) != 0) {
-            fprintf(stderr, "%s: failed to close \"%s\"", name, location);
+            printf("%s: failed to close \"%s\"", name, location);
             result = strdup("");
             goto done;
         }
@@ -260,7 +260,7 @@
     } else if (strcmp(fs_type, "ext4") == 0) {
         int status = make_ext4fs(location, atoll(fs_size), mount_point, sehandle);
         if (status != 0) {
-            fprintf(stderr, "%s: make_ext4fs failed (%d) on %s",
+            printf("%s: make_ext4fs failed (%d) on %s",
                     name, status, location);
             result = strdup("");
             goto done;
@@ -268,7 +268,7 @@
         result = location;
 #endif
     } else {
-        fprintf(stderr, "%s: unsupported fs_type \"%s\" partition_type \"%s\"",
+        printf("%s: unsupported fs_type \"%s\" partition_type \"%s\"",
                 name, fs_type, partition_type);
     }
 
@@ -394,13 +394,13 @@
         ZipArchive* za = ((UpdaterInfo*)(state->cookie))->package_zip;
         const ZipEntry* entry = mzFindZipEntry(za, zip_path);
         if (entry == NULL) {
-            fprintf(stderr, "%s: no %s in package\n", name, zip_path);
+            printf("%s: no %s in package\n", name, zip_path);
             goto done2;
         }
 
         FILE* f = fopen(dest_path, "wb");
         if (f == NULL) {
-            fprintf(stderr, "%s: can't open %s for write: %s\n",
+            printf("%s: can't open %s for write: %s\n",
                     name, dest_path, strerror(errno));
             goto done2;
         }
@@ -426,14 +426,14 @@
         ZipArchive* za = ((UpdaterInfo*)(state->cookie))->package_zip;
         const ZipEntry* entry = mzFindZipEntry(za, zip_path);
         if (entry == NULL) {
-            fprintf(stderr, "%s: no %s in package\n", name, zip_path);
+            printf("%s: no %s in package\n", name, zip_path);
             goto done1;
         }
 
         v->size = mzGetZipEntryUncompLen(entry);
         v->data = malloc(v->size);
         if (v->data == NULL) {
-            fprintf(stderr, "%s: failed to allocate %ld bytes for %s\n",
+            printf("%s: failed to allocate %ld bytes for %s\n",
                     name, (long)v->size, zip_path);
             goto done1;
         }
@@ -460,13 +460,13 @@
         *p = '\0';
         if (make_parents(name) < 0) return -1;
         int result = mkdir(name, 0700);
-        if (result == 0) fprintf(stderr, "symlink(): created [%s]\n", name);
+        if (result == 0) printf("symlink(): created [%s]\n", name);
         *p = '/';
         if (result == 0 || errno == EEXIST) {
             // successfully created or already existed; we're done
             return 0;
         } else {
-            fprintf(stderr, "failed to mkdir %s: %s\n", name, strerror(errno));
+            printf("failed to mkdir %s: %s\n", name, strerror(errno));
             return -1;
         }
     }
@@ -494,18 +494,18 @@
     for (i = 0; i < argc-1; ++i) {
         if (unlink(srcs[i]) < 0) {
             if (errno != ENOENT) {
-                fprintf(stderr, "%s: failed to remove %s: %s\n",
+                printf("%s: failed to remove %s: %s\n",
                         name, srcs[i], strerror(errno));
                 ++bad;
             }
         }
         if (make_parents(srcs[i])) {
-            fprintf(stderr, "%s: failed to symlink %s to %s: making parents failed\n",
+            printf("%s: failed to symlink %s to %s: making parents failed\n",
                     name, srcs[i], target);
             ++bad;
         }
         if (symlink(target, srcs[i]) < 0) {
-            fprintf(stderr, "%s: failed to symlink %s to %s: %s\n",
+            printf("%s: failed to symlink %s to %s: %s\n",
                     name, srcs[i], target, strerror(errno));
             ++bad;
         }
@@ -574,12 +574,12 @@
 
         for (i = 3; i < argc; ++i) {
             if (chown(args[i], uid, gid) < 0) {
-                fprintf(stderr, "%s: chown of %s to %d %d failed: %s\n",
+                printf("%s: chown of %s to %d %d failed: %s\n",
                         name, args[i], uid, gid, strerror(errno));
                 ++bad;
             }
             if (chmod(args[i], mode) < 0) {
-                fprintf(stderr, "%s: chmod of %s to %o failed: %s\n",
+                printf("%s: chmod of %s to %o failed: %s\n",
                         name, args[i], mode, strerror(errno));
                 ++bad;
             }
@@ -720,7 +720,7 @@
                                int data_len, void* ctx) {
     int r = mtd_write_data((MtdWriteContext*)ctx, (const char *)data, data_len);
     if (r == data_len) return true;
-    fprintf(stderr, "%s\n", strerror(errno));
+    printf("%s\n", strerror(errno));
     return false;
 }
 
@@ -752,14 +752,14 @@
     mtd_scan_partitions();
     const MtdPartition* mtd = mtd_find_partition_by_name(partition);
     if (mtd == NULL) {
-        fprintf(stderr, "%s: no mtd partition named \"%s\"\n", name, partition);
+        printf("%s: no mtd partition named \"%s\"\n", name, partition);
         result = strdup("");
         goto done;
     }
 
     MtdWriteContext* ctx = mtd_write_partition(mtd);
     if (ctx == NULL) {
-        fprintf(stderr, "%s: can't write mtd partition \"%s\"\n",
+        printf("%s: can't write mtd partition \"%s\"\n",
                 name, partition);
         result = strdup("");
         goto done;
@@ -772,7 +772,7 @@
         char* filename = contents->data;
         FILE* f = fopen(filename, "rb");
         if (f == NULL) {
-            fprintf(stderr, "%s: can't open %s: %s\n",
+            printf("%s: can't open %s: %s\n",
                     name, filename, strerror(errno));
             result = strdup("");
             goto done;
@@ -793,15 +793,15 @@
         success = (wrote == contents->size);
     }
     if (!success) {
-        fprintf(stderr, "mtd_write_data to %s failed: %s\n",
+        printf("mtd_write_data to %s failed: %s\n",
                 partition, strerror(errno));
     }
 
     if (mtd_erase_blocks(ctx, -1) == -1) {
-        fprintf(stderr, "%s: error erasing blocks of %s\n", name, partition);
+        printf("%s: error erasing blocks of %s\n", name, partition);
     }
     if (mtd_write_close(ctx) != 0) {
-        fprintf(stderr, "%s: error closing write of %s\n", name, partition);
+        printf("%s: error closing write of %s\n", name, partition);
     }
 
     printf("%s %s partition\n",
@@ -988,23 +988,23 @@
     memcpy(args2, args, sizeof(char*) * argc);
     args2[argc] = NULL;
 
-    fprintf(stderr, "about to run program [%s] with %d args\n", args2[0], argc);
+    printf("about to run program [%s] with %d args\n", args2[0], argc);
 
     pid_t child = fork();
     if (child == 0) {
         execv(args2[0], args2);
-        fprintf(stderr, "run_program: execv failed: %s\n", strerror(errno));
+        printf("run_program: execv failed: %s\n", strerror(errno));
         _exit(1);
     }
     int status;
     waitpid(child, &status, 0);
     if (WIFEXITED(status)) {
         if (WEXITSTATUS(status) != 0) {
-            fprintf(stderr, "run_program: child exited with status %d\n",
+            printf("run_program: child exited with status %d\n",
                     WEXITSTATUS(status));
         }
     } else if (WIFSIGNALED(status)) {
-        fprintf(stderr, "run_program: child terminated by signal %d\n",
+        printf("run_program: child terminated by signal %d\n",
                 WTERMSIG(status));
     }
 
@@ -1053,7 +1053,7 @@
     }
 
     if (args[0]->size < 0) {
-        fprintf(stderr, "%s(): no file contents received", name);
+        printf("%s(): no file contents received", name);
         return StringValue(strdup(""));
     }
     uint8_t digest[SHA_DIGEST_SIZE];
@@ -1068,12 +1068,12 @@
     uint8_t* arg_digest = malloc(SHA_DIGEST_SIZE);
     for (i = 1; i < argc; ++i) {
         if (args[i]->type != VAL_STRING) {
-            fprintf(stderr, "%s(): arg %d is not a string; skipping",
+            printf("%s(): arg %d is not a string; skipping",
                     name, i);
         } else if (ParseSha1(args[i]->data, arg_digest) != 0) {
             // Warn about bad args and skip them.
-            fprintf(stderr, "%s(): error parsing \"%s\" as sha-1; skipping",
-                    name, args[i]->data);
+            printf("%s(): error parsing \"%s\" as sha-1; skipping",
+                   name, args[i]->data);
         } else if (memcmp(digest, arg_digest, SHA_DIGEST_SIZE) == 0) {
             break;
         }