diff --git a/notmuch-insert.c b/notmuch-insert.c
index 00c00468..e3d87e4a 100644
--- a/notmuch-insert.c
+++ b/notmuch-insert.c
@@ -34,7 +34,7 @@ static volatile sig_atomic_t interrupted;
 static void
 handle_sigint (unused (int sig))
 {
-    static char msg[] = "Stopping...         \n";
+    static const char msg[] = "Stopping...         \n";
 
     /* This write is "opportunistic", so it's okay to ignore the
      * result.  It is not required for correctness, and if it does
diff --git a/notmuch-new.c b/notmuch-new.c
index 993359d6..1162e25a 100644
--- a/notmuch-new.c
+++ b/notmuch-new.c
@@ -81,7 +81,7 @@ static volatile sig_atomic_t interrupted;
 static void
 handle_sigint (unused (int sig))
 {
-    static char msg[] = "Stopping...         \n";
+    static const char msg[] = "Stopping...         \n";
 
     /* This write is "opportunistic", so it's okay to ignore the
      * result.  It is not required for correctness, and if it does
diff --git a/notmuch-reindex.c b/notmuch-reindex.c
index 8904c1f4..a7380a4b 100644
--- a/notmuch-reindex.c
+++ b/notmuch-reindex.c
@@ -26,7 +26,7 @@ static volatile sig_atomic_t interrupted;
 static void
 handle_sigint (unused (int sig))
 {
-    static char msg[] = "Stopping...         \n";
+    static const char msg[] = "Stopping...         \n";
 
     /* This write is "opportunistic", so it's okay to ignore the
      * result.  It is not required for correctness, and if it does
diff --git a/notmuch-tag.c b/notmuch-tag.c
index 667a75d6..de428c8e 100644
--- a/notmuch-tag.c
+++ b/notmuch-tag.c
@@ -27,7 +27,7 @@ static volatile sig_atomic_t interrupted;
 static void
 handle_sigint (unused (int sig))
 {
-    static char msg[] = "Stopping...         \n";
+    static const char msg[] = "Stopping...         \n";
 
     /* This write is "opportunistic", so it's okay to ignore the
      * result.  It is not required for correctness, and if it does