diff --git a/debian/changelog b/debian/changelog
index baa9fb4..4e3ced3 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -6,6 +6,7 @@
     + Check if name given as parameter is an executable in $PATH if no
       such file exists. Use File::Which for this and add a Recommends on
       libfile-which-perl accordingly.
+    + Prefix all messages to STDERR with either "E:", "W:", or "I:".
 
  -- Axel Beckert <abe@debian.org>  Sun, 18 Nov 2018 16:53:41 +0100
 
diff --git a/find-dbgsym-packages b/find-dbgsym-packages
index be08a61..2c97368 100755
--- a/find-dbgsym-packages
+++ b/find-dbgsym-packages
@@ -53,10 +53,10 @@
         if (scalar @p == 0) {
             @p = get_debs_from_path($path);
             if (scalar @p == 0) {
-                warn "Cannot find debug package for $name ($id)\n";
+                warn "W: Cannot find debug package for $name ($id)\n";
             }
         } elsif (scalar @p > 1) {
-            warn "Multiple packages for $name ($id): @p\n";
+            warn "W: Multiple packages for $name ($id): @p\n";
         }
         foreach my $p (@p) {
             $pkgs{$p} = 1;
@@ -104,7 +104,7 @@
                 next;
             }
             if ($id eq '-') {
-                warn "No build-ID for $name\n";
+                warn "W: No build-ID for $name\n";
                 next;
             } elsif ($id =~ /^([[:xdigit:]]{40})[@]/) {
                 $id = $1;
@@ -117,7 +117,7 @@
             }
             $ids{$id} = [$path, $name];
         } else {
-            warn "Cannot parse eu-unstrip output: '$line'\n";
+            warn "W: Cannot parse eu-unstrip output: '$line'\n";
         }
     }
     return (%ids);
@@ -137,7 +137,7 @@
         } elsif ($line =~ /^\t(.+) \(0x[0-9a-f]+\)$/) {
             push @libs, $1;
         } else {
-            warn "Cannot parse ldd output: '$line'\n";
+            warn "W: Cannot parse ldd output: '$line'\n";
         }
     }
 
@@ -230,7 +230,7 @@
         if ($line =~ /^(.*): /) {
             $pkgs{$1} = 1;
         } else {
-            warn "Cannot parse dpkg-query output: '$line'\n";
+            warn "W: Cannot parse dpkg-query output: '$line'\n";
         }
     }
     my @pkgs = sort keys %pkgs;
@@ -248,7 +248,7 @@
         my $output;
         $output = capturex([0, 1], qw(grep-aptavail --no-field-names --show-field Package --field Package --pattern -dbg --and --whole-pkg --field Source:Package --pattern), $src_pkg);
         if ($EXITVAL) {
-            warn "No dbg package for source '$src_pkg'\n";
+            warn "W: No dbg package for source '$src_pkg'\n";
             next;
         }
         my %src_dbg_pkgs = map { $_ => 1 } split(/\n/, $output);